US3756844A - Zed spangle produkt controlling cooling of galvanized strip in process of forming minimiz - Google Patents

Zed spangle produkt controlling cooling of galvanized strip in process of forming minimiz Download PDF

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Publication number
US3756844A
US3756844A US00167726A US3756844DA US3756844A US 3756844 A US3756844 A US 3756844A US 00167726 A US00167726 A US 00167726A US 3756844D A US3756844D A US 3756844DA US 3756844 A US3756844 A US 3756844A
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United States
Prior art keywords
strip
cooling
molten
spangle
heating
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US00167726A
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English (en)
Inventor
E Bunnell
P Schnedler
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Armco Steel Co LP
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Armco Inc
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Assigned to ARMCO STEEL COMPANY, L.P., A DE LIMITED PARTNERSHIP reassignment ARMCO STEEL COMPANY, L.P., A DE LIMITED PARTNERSHIP ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ARMCO INC., A CORP. OF OHIO
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Expired - Lifetime legal-status Critical Current

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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
    • C23C2/26—After-treatment
    • C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
    • 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
    • C23C2/26—After-treatment
    • C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
    • C23C2/29—Cooling or quenching

Definitions

  • the apparatus includes a manifold arranged transversely of the path of movement of the strip and extending across its full width.
  • the manifold will be supplied with a heating or cooling fluid, and a plurality of nozzles directed at selected longitudinal zones of the strip. Each nozzle is independently controlled so that the fluid is directed only at the desired longitudinal zones of the strip.
  • This invention relates to a method and apparatus for the selective heating and/or cooling of desired longitudinal areas of a moving strip.
  • the invention has great and particular utility in controlling the cooling pattern of a molten metallic coating applied to a ferrous strip.
  • Hot dip metallic coating processes include three steps. The first involves a thorough cleaning of the base metal and perhaps some additional treatment to render the surface of the strip receptive to the molten coating metal.
  • the thoroughly cleaned strip is then passed at a predetermined temperature into a bath of molten coating metal. As the strip is withdrawn from the molten metal bath, it will carry with it a layer of still molten coating metal.
  • This still molten coating must be solidified before the strip can be coiled or otherwise subjected to further processing.
  • the spangle may be considered desirable in that it gives a distinctive appearance to the finished product.
  • the spangle is very undesirable because the crystalline boundaries will show through the finish paint coat.
  • the Water solution of an inorganic salt provides a multitude of closely spaced solidification nuclei, which induce a multitude of closely spaced, minute spangles which are sub-macroscopic, or nearly so.
  • Practice of the teachings of this patent has successfully produced a zinc coated steel strip having an unspangled appearance.
  • FIG. 1 is a schematic view showing the normal cooling pattern of molten metal on a base metal strip.
  • FIG. 2 is a schematic view similar to FIG. 1 showing the desired cooling pattern.
  • FIG. 3 is a schematic view showing the apparatus of this invention for selectively heating or cooling predetermined longitudinal areas of the coated strip.
  • FIG. 4 is a schematic view showing a modification for the invention permitting simultaneous heating and cooling of different, selected longitudinal zones on the strip.
  • this invention relates to a method and apparatus for controlling the cooling and hence solidification of a molten metal coating on a base strip. More specifically, the method of this invention contemplates the step of applying a heating or a cooling fluid to selected longitudinal areas or zones of a ferrous strip as it emerges from a bath of molten metal in order to promote a uniform cooling pattern.
  • the apparatus of this invention contemplates at least one manifold extending transversely across the full width of the strip and communicating with a supply of heating or cooling fluid under pressure.
  • the manifold is provided with a plurality of spaced apart nozzles, each of which is individually controllable, so that the quantity of heating or cooling fluid supplied to any selected longitudinal zone on the moving strip can be regulated.
  • the strip to be coated is thoroughly cleaned and, while maintained in a protective atmosphere, passed into a bath of molten coating metal.
  • the strip is then withdrawn from the bath of molten metal in a generally vertically upward path of travel.
  • the strip Upon emergence from the bath, the strip will carry with it a quantity of molten metal.
  • This molten metal adhering to the strip may be subjected to or controlled by a variety of well known finishing techniques, including exit rolls, jet finishing nozzles, and the like.
  • the method and apparatus of this invention relate to the treatment of the coated strip after it passes the finishing device or devices briefly noted above, and prior to the solidification of the molten coating on the ferrous strip.
  • FIG. 1 it is now known that as the strip bearing the molten coating metal passes the finishing devices, it begins to cool at the edges of the strip. This cooling gradually progresses toward the center of the strip and forms, in effect, an inverted parabolic cooling pattern.
  • a portion of a strip indicated generally at is moving in a vertically upward path of travel.
  • the portion of the strip 12 will include solidified coating metal, while a portion 14 will have still molten coating metal on the surface.
  • the inverted parabolic line 16 defines the boundary between the solidified and molten portions of the coating metal.
  • the desired cooling pattern is indicated schematically in FIG. 2.
  • a portion of a strip moving vertically upward is indicated at 10'.
  • the portion of the strip 12' is covered by solidified coating metal, while the portion 14' contains still molten coating metal.
  • the line of demarcation between the solidified and the molten metal is indicated at 16, and it will be seen that it approaches a straight line normal to the path of movement of the strip.
  • FIGS. 3 and 4 show schematically two embodiments of the invention.
  • the molten coating metal level in the bath is indicated at 18, and the strip indicated generally at 20 is moved by conventional means in a vertically upward path from the bath.
  • the finishing of the metallic coating is accomplished by the jet nozzle indicated schematically at 22.
  • the rectangle 24 is a schematic illustration of the device which is utilized to apply the solidification nuclei consisting of a water solution of a salt to the molten coating. It will of course be understood that the device 24 will be vertically movable so as to permit variations in the point at which the solidification nuclei are applied to the strip.
  • the method of this invention contemplates the step of selectively heating and/or cooling desired longitudinal areas of a moving strip, so as to control the cooling pattern.
  • the objective is to change from the normal cooling pattern set forth in FIG. 1 to the desired pattern shown in FIG. 2.
  • this is accomplished by means of the manifold 26 which will be connected to a suitable source of fluid (not shown) at a temperature substantially different from the temperature of the molten coating metal.
  • the manifold 26 is provided wtih a main control valve 28.
  • the manifold 26 is of a length to extend transversely across the entire strip width.
  • nozzles indicated schematically in FIG. 3 at 30a through 301'.
  • Each of these nozzles is provided with an individual control indicated schematically at 31.
  • a cooling fluid such as air
  • the compressed air normally is supplied to the control valves at a pressure of 25-100 p.s.i. and a temperature of 60-150 F.
  • the nozzles at the center of the strip width (30d, 30c, and 30 would be opened to provide a greater cooling effect in the center of the strip.
  • the nozzles would be adjusted to provide a continuously smaller flow of fluid onto the coating.
  • a heating fluid such as hot combustion gases be supplied to the strip.
  • the temperature of the combustion gases would be in the range of l00O-2500 F. depending on the volume of fuel supplied, efliciency of combustion and distance from the nozzle. Pressure would be slightly above atmospheric.
  • the nozzles at the edge of the strip (30b and 3011) would be opened to a greater extent to provide a greater heating action at the edges of the strip. Progressing toward the center, the nozzles would be adjusted to provide a lesser flow of heating fluid to the strip.
  • the nozzle at each position on the strip will be adjusted as necessary to vary the temperature of that portion or longitudinal zone of the strip with respect to the other zones so as to create a straight line temperature differential across the strip.
  • FIG. 4 illustrates schematically a modification of the invention. Again, the strip is indicated generally at 20, the level of molten metal in the bath at 18, the jet finishing nozzle at 22, and the apparatus for applying solidification nuclei to the strip at 24.
  • two manifolds 32 and 34 are provided, each of which extends across the full width of the strip.
  • the manifold 32 and 34 are provided respectively with the main control valves 36 and 38.
  • the manifold 32 is provided with the individual nozzles 40a through 401', while the manifold 34 is provided with the individual nozzles 42a through 42i.
  • Each of the nozzles 40a through 401 is provided with an individual control valve 41, while each of the nozzles 42a through 421' is provided with an individual control valve 43.
  • a heating fluid will be supplied to one of the manifolds, and a cooling fluid will be supplied to the other.
  • a heating fluid will be supplied to one of the manifolds, and a cooling fluid will be supplied to the other.
  • certain longitudinal portions of the strip could be cooled while other longitudinal portions are simultaneously being heated.
  • each nozzle control valve could be manually set and/or adjusted. Operating experience would indicate normal settings for each valve under a variety of different conditions.
  • a process for producing a zinc coated ferrous strip having a spangle which is substantially invisible to the naked eye and which includes the steps of cleaning the surface of said strip to render it receptive to the molten zinc, passing said cleaned strip into a bath of said molten zinc, withdrawing said strip from said bath with a quantity of said molten zinc adhering thereto, finishing said molten zinc adhering to said strip, and thereafter inducing sub-macroscopic spangling by applying a multitude of solidification nuclei to said finished molten zinc adhering to said strip when said zinc is at a temperature just above the freezing point; the improved step of controlling the cooling of said finished molten zinc by applying a heating or a cooling fluidto selected longitudinal zones of said strip.
  • step of controlling the cooling of said finished molten zinc includes the steps of:

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  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Thermal 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)
  • Application Of Or Painting With Fluid Materials (AREA)
US00167726A 1971-07-30 1971-07-30 Zed spangle produkt controlling cooling of galvanized strip in process of forming minimiz Expired - Lifetime US3756844A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US16772671A 1971-07-30 1971-07-30

Publications (1)

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US3756844A true US3756844A (en) 1973-09-04

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US00167726A Expired - Lifetime US3756844A (en) 1971-07-30 1971-07-30 Zed spangle produkt controlling cooling of galvanized strip in process of forming minimiz

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US (1) US3756844A (pt)
JP (1) JPS5324896B1 (pt)
AR (1) AR206285A1 (pt)
BE (1) BE786451A (pt)
BR (1) BR7204989D0 (pt)
CA (1) CA999494A (pt)
DE (1) DE2234805C3 (pt)
ES (1) ES405198A1 (pt)
FR (1) FR2148058B1 (pt)
GB (1) GB1400074A (pt)
IT (1) IT961336B (pt)
NL (1) NL7210475A (pt)
SE (1) SE392918B (pt)
ZA (1) ZA724491B (pt)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4158070A (en) * 1978-06-26 1979-06-12 Armstrong Cork Company Selective cooling of sheet to be embossed
US4346129A (en) * 1981-03-02 1982-08-24 Republic Steel Corporation Method and apparatus for thickness control of a coating
US4418100A (en) * 1982-02-02 1983-11-29 Republic Steel Corporation Apparatus and method for reducing spangle in galvanized products
US4527506A (en) * 1984-03-12 1985-07-09 Midland-Ross Coporation Apparatus for cooling a strip prior to a minispangle operation
CN111719103A (zh) * 2020-07-03 2020-09-29 攀钢集团攀枝花钢钒有限公司 一种连续热镀锌铝硅合金镀层钢板/带表面锌花控制方法
CN112593175A (zh) * 2020-12-11 2021-04-02 东北大学 一种热镀锌带钢小锌花生产控温设备及其控制系统

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE7600244L (sv) * 1975-01-13 1976-07-14 Nat Steel Corp Forfarande och anordning for att reglera tjockleken av en vetskebeleggning
US5156683A (en) * 1990-04-26 1992-10-20 Ajax Magnethermic Corporation Apparatus for magnetic induction edge heaters with frequency modulation

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS503980A (pt) * 1973-05-08 1975-01-16

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4158070A (en) * 1978-06-26 1979-06-12 Armstrong Cork Company Selective cooling of sheet to be embossed
US4346129A (en) * 1981-03-02 1982-08-24 Republic Steel Corporation Method and apparatus for thickness control of a coating
US4418100A (en) * 1982-02-02 1983-11-29 Republic Steel Corporation Apparatus and method for reducing spangle in galvanized products
US4527506A (en) * 1984-03-12 1985-07-09 Midland-Ross Coporation Apparatus for cooling a strip prior to a minispangle operation
CN111719103A (zh) * 2020-07-03 2020-09-29 攀钢集团攀枝花钢钒有限公司 一种连续热镀锌铝硅合金镀层钢板/带表面锌花控制方法
CN111719103B (zh) * 2020-07-03 2022-07-12 攀钢集团攀枝花钢钒有限公司 一种连续热镀锌铝硅合金镀层钢板/带表面锌花控制方法
CN112593175A (zh) * 2020-12-11 2021-04-02 东北大学 一种热镀锌带钢小锌花生产控温设备及其控制系统
CN112593175B (zh) * 2020-12-11 2021-09-24 东北大学 一种热镀锌带钢小锌花生产控温设备及其控制系统

Also Published As

Publication number Publication date
ZA724491B (en) 1973-03-28
DE2234805B2 (de) 1977-10-20
AU4420072A (en) 1974-01-10
ES405198A1 (es) 1975-08-16
SE392918B (sv) 1977-04-25
IT961336B (it) 1973-12-10
AR206285A1 (es) 1976-07-15
JPS5324896B1 (pt) 1978-07-24
GB1400074A (en) 1975-07-16
DE2234805A1 (de) 1973-02-08
FR2148058B1 (pt) 1976-05-14
DE2234805C3 (de) 1978-06-15
NL7210475A (pt) 1973-02-01
CA999494A (en) 1976-11-09
BR7204989D0 (pt) 1973-05-03
FR2148058A1 (pt) 1973-03-11
BE786451A (fr) 1972-11-16

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Date Code Title Description
AS Assignment

Owner name: ARMCO STEEL COMPANY, L.P., 703 CURTIS STREET, MIDD

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ARMCO INC., A CORP. OF OHIO;REEL/FRAME:005110/0744

Effective date: 19890511