WO2013056305A1 - Bande d'acier recouverte de métal - Google Patents

Bande d'acier recouverte de métal Download PDF

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Publication number
WO2013056305A1
WO2013056305A1 PCT/AU2012/001262 AU2012001262W WO2013056305A1 WO 2013056305 A1 WO2013056305 A1 WO 2013056305A1 AU 2012001262 W AU2012001262 W AU 2012001262W WO 2013056305 A1 WO2013056305 A1 WO 2013056305A1
Authority
WO
WIPO (PCT)
Prior art keywords
bath
alloy
method defined
weight
composition
Prior art date
Application number
PCT/AU2012/001262
Other languages
English (en)
Inventor
Nega Setargew
Wai Yee Daniel Yuen
Original Assignee
Bluescope Steel Limited
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from AU2011904293A external-priority patent/AU2011904293A0/en
Application filed by Bluescope Steel Limited filed Critical Bluescope Steel Limited
Priority to NZ621776A priority Critical patent/NZ621776B2/en
Priority to AU2012325673A priority patent/AU2012325673B2/en
Publication of WO2013056305A1 publication Critical patent/WO2013056305A1/fr
Priority to US14/256,028 priority patent/US20140227451A1/en
Priority to US16/540,704 priority patent/US20190368022A1/en

Links

Classifications

    • 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
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06—Zinc or cadmium or alloys based thereon
    • 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
    • C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
    • C23C2/36—Elongated material
    • C23C2/40—Plates; Strips
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C18/00—Alloys based on zinc
    • C22C18/04—Alloys based on zinc with aluminium as the next major constituent
    • 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
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C2204/00—End product comprising different layers, coatings or parts of cermet

Definitions

  • the present invention relates to the production of strip, typically steel strip, which has a corrosion- resistant metal alloy coating that contains aluminium- zinc-silicon-magnesium as the main elements in the alloy in the following ranges in % by weight:
  • Al-Zn-Si-Mg alloy Al-Zn-Si-Mg alloy
  • the Al-Zn-Si-Mg alloy coating may contain other elements that are present as deliberate alloying additions or as unavoidable impurities.
  • the phrase "Al-Zn- Si-Mg alloy” is understood herein to cover alloys that contain such other elements as deliberate alloying additions or as unavoidable impurities.
  • the other elements may include by way of example any one or more of Fe, Ti, Cu, Ni, Co, Ca, Mn, Be, Sr, Ca, Cr, and V.
  • the present invention relates to hot-dip metal coating method of forming an Al-Zn-Si-Mg alloy coating on a strip that includes dipping uncoated strip into a bath of molten Al-Zn-Si-Mg alloy and forming a coating of the alloy on the strip.
  • the present invention is concerned with
  • top dross is undesirable from the viewpoints of cost of production and coating quality, as is discussed further below.
  • top dross is herein understood to include any one or more of the following components on or near the surface of the molten bath:
  • Items (b) , (c) , (d) , and (e) can be described as the result of entrainment of molten metal, gas, and intermetallic particles in the oxide film on or near the surface of the molten bath.
  • the invention was made during the course of a research and development project that investigated the addition of Mg to a known corrosion resistant metal coating composition, namely 55%A1-Zn-Si, that is used widely in Australia and elsewhere for building products, particularly profiled wall and roofing sheets .
  • a known corrosion resistant metal coating composition namely 55%A1-Zn-Si
  • the addition of Mg to this known composition of 55%A1-Zn-Si coating composition had been proposed in the patent literature for a number of years, see for example US patent 6,635,359 in the name of Nippon Steel
  • Mg when Mg is included in a 55%A1-Zn coating composition, Mg brings about certain beneficial effects on product performance , such as improved cut-edge protection.
  • Mg-containing molten 55%A1-Zn coating metal is susceptible to increased levels of top dross generation compared to molten 55%A1-Zn coating metal that does not contain Mg.
  • the applicant has been able to reduce the top dross levels in molten Al-Zn-Si-Mg alloy baths containing in % by weight: Al : 2 to 19 %, Si: 0.1 to 2%, Mg: 1 to 10 %, and Zn : 80 to 97 % by the addition to molten baths of Ca, and the reduction in top dross levels has lead to benefits in terms of production costs and product quality.
  • a method of forming an Al-Zn-Si-Mg alloy coating on a strip that includes dipping strip into a bath of molten Al-Zn-Si-Mg alloy and forming a coating of the alloy on the strip, with the Al-Zn-Si-Mg alloy containing in % by weight: Al : 2 to 19 %, Si: 0.1 to 2%, Mg: 1 to 10 %, and Zn : 80 to 97 %, and with the bath having a molten metal layer and a top dross layer on the metal layer, and the method including providing Ca in the composition of the bath to minimise the top dross layer in the molten bath.
  • the Al-Zn-Si-Mg alloy may contain other elements that are present as deliberate alloying additions or as unavoidable impurities.
  • the phrase "Al-Zn-Si-Mg alloy” is understood herein to cover alloys that contain such other elements as deliberate alloying additions or as unavoidable impurities .
  • the other elements may include by way of example any one or more of Fe, Ti, Cu, Ni, Co, Ca, n, Be, Sr, Cr, and V.
  • the composition of the bath may include more than 50 ppm Ca . It is noted that all references to ppm in the specification are references to ppm by weight.
  • composition of the bath may include more than 100 ppm Ca.
  • composition of the bath may include more than 200 ppm Ca.
  • composition of the bath may include more than
  • composition of the bath may include more than 300 ppm Ca.
  • composition of the bath may include less than 2000 ppm Ca.
  • composition of the bath may include less than 1500 ppm Ca.
  • composition of the bath may include less than 1000 ppm Ca.
  • references to amounts of elements such as Ca as part of the composition of a molten bath are understood herein to be references to the concentrations of the elements in the molten metal layer of the bath as opposed to the top dross layer in the bath. The reason for this is that it is the standard practice of the applicant to measure bath concentrations in the molten metal layers of molten baths .
  • the top dross layer of the bath there will be a higher concentration of the element in the top dross layer of the bath .
  • the Ca may be added to the bath as required. It could be by way of specific additions of Ca compounds on a continuous or a periodic basis. It could also be by way of the inclusion of Ca in Al and/or Zn ingots that are provided as feed materials for the bath .
  • the method may include controlling the concentration of Ca in the bath to minimise the top dross layer in the molten bath.
  • the method may include controlling the
  • composition of the bath to minimise the top dross layer in the bath by periodically monitoring the concentration of Ca that is in the bath, and adding Ca as required to maintain the bath composition for the element.
  • the method may include selecting any one or more of the sizes of the ingots , the timing of the addition of the ingots , and the sequence of the addition of the ingots to maintain the concentration of Ca substantially constant or within a preferred range of + or - 10% for the elements.
  • the Al-Zn-Si-Mg alloy may include more than 8 % by weight Al .
  • the Al-Zn-Si-Mg alloy may include more than 10 % by weight Al .
  • the Al-Zn-Si-Mg alloy may include less than 15 % by weight Al .
  • the Al-Zn-Si-Mg alloy may include less than 12 % by weight Al.
  • the Al-Zn-Si-Mg alloy may include more than 0.3 % by weight Mg.
  • the Al-Zn-Si-Mg alloy may include more than 1 % by weight Mg.
  • the Al-Zn-Si-Mg alloy may include more than 2 % by weight Mg.
  • the Al-Zn-Si-Mg alloy may include more than 2.5 3 ⁇ 4 by weight Mg.
  • the Al-Zn-Si-Mg alloy may include more than 3 % by weight Mg.
  • the Al-Zn-Si-Mg alloy may include less than 5 % by weight Mg.
  • the Al-Zn-Si-Mg alloy may include less than 4 % by weight Mg.
  • the Al-Zn-Si-Mg alloy may include more than 0.15 % by weight Si .
  • the Al-Zn-Si-Mg alloy may include less than 1.2 % by weight Si.
  • the Al-Zn-Si-Mg alloy may include less than 1 % by weight Si .
  • the Al-Zn-Si-Mg alloy may include less than 0.25
  • Figure 1 is a schematic drawing of one embodiment of a continuous production line for producing steel strip coated with an Al-Zn-Si-Mg alloy in accordance with the method of the present invention
  • Figure 2 is a graph of the mass of dross versus Ca concentration for molten Al-Zn-Si-Mg alloy baths with and without Ca in experiments on dross generation carried out by the applicant.
  • coils of cold rolled steel strip are uncoiled at an uncoiling station 1 and successive uncoiled lengths of strip are welded end to end by a welder 2 and form a continuous length of strip .
  • the strip is then passed successively through an accumulator 3 , a strip cleaning section 4 and a furnace assembly 5.
  • the furnace assembly 5 includes a preheater, a preheat reducing furnace , and a reducing furnace .
  • the strip is heat treated in the furnace assembly 5 by careful control of process variables including: (i) the temperature profile in the furnaces, (ii) the reducing gas concentration in the furnaces, (iii) the gas flow rate through the furnaces, and (iv) strip residence time in the furnaces (i.e. line speed).
  • the process variables in the furnace assembly 5 are controlled so that there is removal of iron oxide residues from the surface of the strip and removal of residual oils and iron fines from the surface of the strip .
  • the heat treated strip is then passed via an outlet snout downwardly into and through a molten bath containing an Al-Zn-Si-Mg alloy held in a coating pot 6 and is coated with Al-Zn-Si-Mg alloy.
  • the Al-Zn-Si-Mg alloy is maintained molten in the coating pot by use of heating inductors (not shown) .
  • Heating inductors not shown
  • Within the bath the strip passes around a sink roll and is taken upwardly out of the bath. Both surfaces of the strip are coated with the Al- Zn-Si-Mg alloy as it passes through the bath.
  • the strip After leaving the coating bath 6 the strip passes vertically through a gas wiping station (not shown) at which its coated surfaces are subjected to jets of wiping gas to control the thickness of the coating.
  • the coated strip is then passed through a cooling section 7 and subjected to forced cooling.
  • the cooled, coated strip is then passed through a rolling section 8 that conditions the surface of the coated strip.
  • the coated strip is thereafter coiled at a coiling station 10.
  • Al-Zn-Si-Mg alloy coating baths containing in % by weight: Al : 2 to 19 %, Si: 0.1 to 2%, Mg: 1 to 10 %, and Zn: 80 to 97 % generate substantial amounts of top dross in the baths that is undesirable in terms of production costs and product quality.
  • concentrations of Ca are the concentrations of these elements in the metallic parts of molten baths .
  • the dross collector cup and the impellor were fabricated from a high temperature material that is non- wetting to the coating alloy tested in the experimental work .
  • Figure 2 is a graph of the mass of dross generated versus Ca concentration for the molten alloy baths .
  • Figure 2 clearly shows that the level of top dross generated in an Al-Zn-Si-Mg alloy bath can be significantly reduced by additions of Ca to coating baths More particularly, Figure 2 shows that the amount of top dross decreases significantly with increasing amounts of Ca in the coating baths .
  • the Ca may be added to a coating bath as required. It could be by way of specific additions of Ca compounds on a continuous or a periodic basis. It could also be by way of the inclusion of Ca and/or in Al and/or Zn ingots that are provided as feed materials for the bath.

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

Abstract

La présente invention se rapporte à un procédé de formation d'un revêtement d'alliage de Al-Zn-Si-Mg sur une bande, qui consiste à plonger une bande dans un bain d'alliage de Al-Zn-Si-Mg fondu et à former un revêtement de l'alliage sur la bande, l'alliage de Al-Zn-Si-Mg contenant, en % en poids : une quantité d'aluminium (Al) comprise entre 2 et 19 % ; une quantité de silicium (Si) comprise entre 0,1 et 2 % ; une quantité de magnésium (Mg) comprise entre 1 et 10 % ; et une quantité de zinc (Zn) comprise entre 80 et 97 %, le bain comprenant une couche de métal fondu et une couche d'écume de surface agencée sur la couche de métal, et le procédé consistant à utiliser du calcium (Ca) dans la composition du bain pour réduire à un minimum la couche d'écume de surface dans le bain fondu.
PCT/AU2012/001262 2011-10-18 2012-10-18 Bande d'acier recouverte de métal WO2013056305A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
NZ621776A NZ621776B2 (en) 2011-10-18 2012-10-18 Metal-coated steel strip
AU2012325673A AU2012325673B2 (en) 2011-10-18 2012-10-18 Metal-coated steel strip
US14/256,028 US20140227451A1 (en) 2011-10-18 2014-04-18 Metal-coated steel strip
US16/540,704 US20190368022A1 (en) 2011-10-18 2019-08-14 Metal-coated steel strip

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU2011904293A AU2011904293A0 (en) 2011-10-18 Metal-Coated Steel Strip
AU2011904293 2011-10-18

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US14/256,028 Continuation US20140227451A1 (en) 2011-10-18 2014-04-18 Metal-coated steel strip

Publications (1)

Publication Number Publication Date
WO2013056305A1 true WO2013056305A1 (fr) 2013-04-25

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU2012/001262 WO2013056305A1 (fr) 2011-10-18 2012-10-18 Bande d'acier recouverte de métal

Country Status (3)

Country Link
US (2) US20140227451A1 (fr)
AU (1) AU2012325673B2 (fr)
WO (1) WO2013056305A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150267287A1 (en) * 2012-10-18 2015-09-24 Bluescope Steel Limited Method of producing metal coated steel strip
US11613792B2 (en) 2012-10-17 2023-03-28 Bluescope Steel Limited Method of producing metal-coated steel strip

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11384419B2 (en) * 2019-08-30 2022-07-12 Micromaierials Llc Apparatus and methods for depositing molten metal onto a foil substrate

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000071773A1 (fr) * 1999-05-24 2000-11-30 Nippon Steel Corporation Produit d'acier plaque, feuille d'acier plaquee et feuille d'acier prerevetue possedant une excellente resistance a la corrosion
EP1466994B1 (fr) * 2002-01-09 2011-01-05 Nippon Steel Corporation Plaque en acier a placage en zinc excellente en resistance a la corrosion apres revetement et clarte du revetement
US20110268984A1 (en) * 2003-03-20 2011-11-03 Bluescope Steel Limited Method of controlling surface defects in metal-coated strip

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NZ575787A (en) * 2006-08-29 2012-03-30 Bluescope Steel Ltd Steel strip coated with aluminum, zinc, silicon and magnesium alloy
KR20170125139A (ko) * 2010-01-25 2017-11-13 블루스코프 스틸 리미티드 금속-코팅된 강철 스트립

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000071773A1 (fr) * 1999-05-24 2000-11-30 Nippon Steel Corporation Produit d'acier plaque, feuille d'acier plaquee et feuille d'acier prerevetue possedant une excellente resistance a la corrosion
EP1466994B1 (fr) * 2002-01-09 2011-01-05 Nippon Steel Corporation Plaque en acier a placage en zinc excellente en resistance a la corrosion apres revetement et clarte du revetement
US20110268984A1 (en) * 2003-03-20 2011-11-03 Bluescope Steel Limited Method of controlling surface defects in metal-coated strip

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11613792B2 (en) 2012-10-17 2023-03-28 Bluescope Steel Limited Method of producing metal-coated steel strip
US20150267287A1 (en) * 2012-10-18 2015-09-24 Bluescope Steel Limited Method of producing metal coated steel strip
AU2013332256B2 (en) * 2012-10-18 2018-03-22 Bluescope Steel Limited Method of producing metal coated steel strip

Also Published As

Publication number Publication date
US20190368022A1 (en) 2019-12-05
US20140227451A1 (en) 2014-08-14
AU2012325673A1 (en) 2014-03-27
AU2012325673B2 (en) 2017-07-06
NZ621776A (en) 2016-03-31

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