WO2024214329A1 - TÔLE D'ACIER PLAQUÉE À BASE D'Al-Zn FONDU ET SON PROCÉDÉ DE FABRICATION - Google Patents

TÔLE D'ACIER PLAQUÉE À BASE D'Al-Zn FONDU ET SON PROCÉDÉ DE FABRICATION Download PDF

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WO2024214329A1
WO2024214329A1 PCT/JP2023/040988 JP2023040988W WO2024214329A1 WO 2024214329 A1 WO2024214329 A1 WO 2024214329A1 JP 2023040988 W JP2023040988 W JP 2023040988W WO 2024214329 A1 WO2024214329 A1 WO 2024214329A1
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mass
steel sheet
hot
dip
plating film
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PCT/JP2023/040988
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English (en)
Japanese (ja)
Inventor
昌浩 吉田
章一郎 平
純久 岩野
洋平 佐藤
史嵩 菅野
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JFE Steel Corp
JFE Galvanizing and Coating Co Ltd
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JFE Steel Corp
JFE Galvanizing and Coating Co Ltd
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Priority to KR1020257032155A priority Critical patent/KR20250164208A/ko
Priority to JP2024517175A priority patent/JPWO2024214329A1/ja
Priority to CN202380097005.8A priority patent/CN120917177A/zh
Publication of WO2024214329A1 publication Critical patent/WO2024214329A1/fr
Anticipated expiration legal-status Critical
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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
    • C23C2/04—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
    • C23C2/12—Aluminium or alloys based thereon
    • 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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C22C21/10—Alloys based on aluminium with zinc as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C30/00—Alloys containing less than 50% by weight of each constituent
    • C22C30/06—Alloys containing less than 50% by weight of each constituent containing zinc
    • 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
    • C23C2/26—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
    • C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
    • C23C30/005—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process on hard metal substrates

Definitions

  • the present invention relates to hot-dip Al-Zn-plated steel sheets that have stable and excellent workability and corrosion resistance in processed areas, and to a method for manufacturing the same.
  • Hot-dip Al-Zn-plated steel sheets typified by 55% Al-Zn, are known to exhibit high corrosion resistance among hot-dip galvanized steel sheets because they combine the sacrificial corrosion protection properties of Zn with the high corrosion resistance of Al, as disclosed in Patent Document 1, for example.
  • hot-dip Al-Zn coated steel sheets are mainly used in the field of building materials such as roofs and walls that are exposed outdoors for long periods of time, and in the field of civil engineering and construction such as guardrails, wiring and piping, soundproof walls, etc.
  • the coating of hot-dip Al-Zn-plated steel sheets is composed of areas where Al containing supersaturated Zn has solidified into dendrites ( ⁇ -Al phase) and a Zn-Al eutectic structure that exists in the gaps between dendrites (interdendrites), and is characterized by a structure in which the ⁇ -Al phase is layered in the thickness direction of the coating.
  • This characteristic coating structure makes the corrosion progression path from the surface complex, making it difficult for corrosion to progress easily, and it is also known that hot-dip Al-Zn-plated steel sheets can achieve superior corrosion resistance compared to hot-dip galvanized steel sheets with the same coating thickness.
  • hot-dip Al-Zn plated steel sheet is produced by using a thin steel sheet obtained by hot-rolling or cold-rolling a slab as a base steel sheet, and subjecting the base steel sheet to recrystallization annealing and hot-dip plating treatment in an annealing furnace of a continuous hot-dip plating facility.
  • Si is usually added to the coating bath to suppress the excessive growth of the interfacial alloy layer that forms at the interface between the base steel (base steel sheet) and the coating.
  • This action of Si makes it possible to control the thickness of the interfacial alloy layer of hot-dip Al-Zn coated steel sheets to about 1 to 5 ⁇ m. For a given coating thickness, the thinner the interfacial alloy layer, the thicker the main layer that exhibits high corrosion resistance will be. Therefore, it is known that suppressing the growth of the interfacial alloy layer leads to improved corrosion resistance.
  • Patent Documents 2 and 3 disclose a manufacturing method of hot-dip Al-Zn-plated steel sheet in which the workability is improved by subjecting the hot-dip Al-Zn-plated steel sheet to a specified heat treatment.
  • hot-dip Al-Zn plated steel sheets do not necessarily exhibit excellent workability in cases where impurities are mixed into the plated film, and further improvements are needed to obtain stable excellent workability and corrosion resistance in the processed parts.
  • hot-dip plating In the manufacture of hot-dip plating, it is generally known that impurities inevitably get mixed into the plating bath, and hot-dip Al-Zn plating is no exception. Impurities that get mixed into the plating film include impurities contained in the plating raw materials, and Fe, Cr, Ni, Cu, Co, W, Mg, Ca, etc. that get mixed in due to elution from the base steel sheet or bath-immersed equipment, and these components are inevitably included in the plating film.
  • the production volume of hot-dip Zn-Al-Mg coated steel sheets and hot-dip Al-Zn-Si-Mg coated steel sheets, which have high corrosion resistance has increased in recent years.
  • Mg is often mixed into the coating bath as an impurity, and ultimately into the coating film.
  • unavoidable impurities in the plating film may cause deterioration of the properties of the hot-dip plated steel sheet, such as the appearance, corrosion resistance, and workability, and the presence or absence of the effect of impurities often depends on the composition of the plating film and the impurity concentration.
  • impurities of the same composition may be harmful to the properties of the plated steel sheet in some cases and harmless in other cases.
  • the effect of impurities on the properties of each hot-dip plated steel sheet is investigated, and technologies for controlling the impurity concentration have been developed to stably obtain the required properties.
  • Patent Document 4 discloses a hot-dip galvanized steel sheet having excellent appearance, which contains, in mass %, 0.10 to 0.6% Al, 0.03 to 0.3% Bi, and the balance Zn and unavoidable impurities, with the contents of each of Pb, Sn, and Cd as the unavoidable impurities controlled to 0.002%.
  • Patent Document 5 discloses a hot-dip Zn-Al-Mg plated steel sheet having excellent corrosion resistance, which contains 4.4 to 5.6% Al, 0.3 to 0.56% Mg, with the balance being Zn and unavoidable impurities, and in which the content of Ni as one of the unavoidable impurities is controlled so as not to be contained.
  • Patent Documents 4 and 5 focus on improving corrosion resistance, and do not fully consider the effects of unavoidable impurities on workability and corrosion resistance of processed parts for hot-dip Zn-Al-plated steel sheets that do not contain Mg, or hot-dip Al-Zn-plated steel sheets with a high Al concentration.
  • the present invention aims to provide a hot-dip Al-Zn-plated steel sheet that reliably and stably has excellent workability and corrosion resistance in processed areas, and a manufacturing method thereof.
  • the inventors have noticed that it is important to control the concentration and state of Mg contained as an optional component or unavoidable impurity in the hot-dip Al-Zn-plated film of hot-dip Al - Zn-plated steel sheets, and have found that by keeping the Mg content low and eliminating MgZn2 and Mg2Zn11 in the plating film, excellent workability and corrosion resistance in the processed parts can be reliably and stably obtained.
  • a hot-dip Al-Zn-plated steel sheet having a plating film has a composition containing 45 to 65 mass% Al, 1.0 to 3.0 mass% Si, and the remainder being Zn and unavoidable impurities, The Mg content relative to the total mass of the plating film is 0.3 mass% or less
  • the hot-dip Al-Zn plated steel sheet is characterized in that the diffraction intensities of MgZn 2 and Mg 2 Zn 11 in the plated film, as determined by an X-ray diffraction method, satisfy the following relationships (1) and (2).
  • the hot-dip Al-Zn plated steel sheet according to 1 or 2 above characterized in that the plating film has a total content of unavoidable impurities of 5.0 mass% or less. 4.
  • a method for producing a hot-dip Al-Zn-plated steel sheet having a plating film comprising the steps of: forming the plating film on a base steel sheet using a plating bath having a composition containing 45 to 65 mass% Al and 1.0 to 3.0 mass% Si, with the balance being Zn and unavoidable impurities, in which the Mg content relative to the total mass of the plating bath is controlled to 0.3 mass% or less; a heating temperature T, which is a maximum temperature reached when reheating the steel sheet on which the plating film is formed, is set to 130 to 300°C, and an average cooling rate C (°C/hr) from the heating temperature T (°C) to 100°C after the heating satisfies the following relationship (3): C ⁇ (T-100)/2...(3) 6.
  • the method for producing a hot-dip Al-Zn coated steel sheet according to 5 above characterized in that the coating bath further contains 0.01 to 3.0 mass % in total of one or more elements selected from B, Ca, Ti, V, Cr, Mn, Sr, Mo, In, Sn, Sb, Ce, and Bi. 7.
  • the hot-dip Al-Zn coated steel sheet according to 5 or 6 above characterized in that the content of unavoidable impurities in the coating bath is 5.0 mass% or less in total.
  • the present invention provides a hot-dip Al-Zn-plated steel sheet and its manufacturing method that has reliable and stable excellent workability and corrosion resistance in the processed area.
  • FIG. 1 is an enlarged schematic view of a cross section of a hot-dip Al-Zn plated steel sheet according to an embodiment of the present invention.
  • the hot-dip Al-Zn plated steel sheet of the present invention has a plating film 20 on the surface of a base steel sheet 10.
  • the plating film 20 has a main layer 21 and an interfacial alloy layer 22 formed at the interface between the main layer and the base steel sheet 10.
  • the plating film 20 has a composition containing 45 to 65 mass % Al, 1.0 to 3.0 mass % Si, and the remainder being Zn and unavoidable impurities.
  • the Al content in the plating film is 45 to 65 mass%, preferably 50 to 60 mass%, in consideration of the balance between corrosion resistance and operational aspects. This is because if the Al content in the plating film is at least 45 mass%, dendritic solidification of Al occurs, and a plating film structure mainly composed of ⁇ -Al phase dendritic solidification structure can be obtained.
  • the dendritic solidification structure has a structure in which it is layered in the thickness direction of the plating film, which complicates the corrosion progression path and improves the corrosion resistance of the plating film itself.
  • the more the ⁇ -Al phase dendrite parts are layered the more complex the corrosion progression path becomes, making it difficult for corrosion to reach the base steel sheet, and improving the corrosion resistance.
  • the Al content in the plating film is 50 mass% or more.
  • the Al content in the plating film exceeds 65 mass%, most of the Zn changes to a structure in which it is solid-solved in ⁇ -Al, and the dissolution reaction of the ⁇ -Al phase cannot be suppressed, and the corrosion resistance of the hot-dip Al-Zn plating deteriorates.
  • the Al content in the plating film must be 65% by mass or less, and preferably 60% by mass or less.
  • the Si in the plating film is added mainly to suppress the growth of the Fe-Al and/or Fe-Al-Si interfacial alloy layer that forms at the interface with the base steel sheet, and to prevent the deterioration of the adhesion between the plating film and the steel sheet.
  • an alloying reaction occurs between the Fe on the steel sheet surface and the Al and Si in the bath, and an Fe-Al and/or Fe-Al-Si intermetallic compound layer forms at the interface between the base steel sheet and the plating film.
  • the Si content in the plating film must be 1.0 mass% or more.
  • the Si content in the plating film exceeds 3.0 mass%, not only will the aforementioned effect of inhibiting the growth of the interfacial alloy layer saturate, but the presence of excess Si phase in the plating film will also reduce workability, so the Si content should be 3.0% or less.
  • the plating film contains Zn and unavoidable impurities.
  • the unavoidable impurities contain Fe. This Fe is inevitably contained in the plating film as a result of dissolution of the steel sheet or bath-immersed equipment into the plating bath, and as a result of being supplied by diffusion from the base steel sheet during the formation of the interface alloy layer.
  • the Fe content in the plating film is usually about 0.3 to 2.0 mass%.
  • Other unavoidable impurities include Cr, Ni, Cu, Co, W, Mg, Ca, etc.
  • the total content of unavoidable impurities in the plating film is not particularly limited, but if contained in excess, it may affect various properties of the plated steel sheet, so it is preferable that the total content be 5.0 mass% or less, and more preferably 1.0 mass% or less.
  • the hot-dip Al-Zn plated steel sheet of the present invention requires that the Mg content in the plated film is 0.3 mass% or less with respect to the total mass of the plated film. Since Mg contained in the plated film may deteriorate the workability and corrosion resistance of the processed part of the hot-dip Al-Zn plated steel sheet, the deterioration of the workability and corrosion resistance of the processed part can be suppressed by appropriately controlling the Al, Zn and Si contents in the plated film and then reducing the Mg content. From the same viewpoint, the Mg content in the plated film is preferably 0.1 mass% or less with respect to the total mass of the plated film.
  • Mg may be included as an optional component as long as the Mg content is 0.3 mass% or less with respect to the total mass of the plating film.
  • Mg is not included as an optional added component of the plating film.
  • the Mg content in the inevitable impurities of the plating film is preferably 0.3 mass% or less with respect to the total mass of the plating film, and more preferably 0.1 mass%.
  • the lower the Mg content in the plating film the better the corrosion resistance of the hot-dip Al-Zn-plated steel sheet of the present invention, so there is no particular lower limit.
  • the lower limit of the Mg content in the plating film is substantially about 0.001 mass%.
  • the hot-dip Al-Zn plated steel sheet of the present invention is characterized in that the diffraction intensities of MgZn 2 and Mg 2 Zn 11 in the plated coating, as measured by an X-ray diffraction method, satisfy the following relationship expressions (1) and (2).
  • MgZn 2 (100) 0...(1)
  • Mg 2 Zn 11 (321) 0...(2)
  • MgZn 2 (100): Diffraction intensity of the (100) plane of MgZn 2 (plane spacing d 0.4510 nm)
  • MgZn2 and Mg2Zn11 When a small amount of Mg is contained in the plating film, MgZn2 and Mg2Zn11 may be generated in the plating film , and MgZn2 and Mg2Zn11 , which are intermetallic compounds, generally have hard and brittle properties. Therefore, if such intermetallic compounds are present in the plating film, they may become the starting point of cracks when subjected to severe bending or stretching, causing deterioration of the workability and corrosion resistance of the processed part of the hot-dip Al-Zn-plated steel sheet.
  • the method for measuring MgZn 2 (100) and Mg 2 Zn 11 (321) by X-ray diffraction can be calculated by mechanically scraping off a part of the plating film, powdering it, and then subjecting it to X-ray diffraction (powder X-ray diffraction measurement method).
  • the amount of the plating film required for carrying out the powder X-ray diffraction measurement is 0.1 g or more, preferably 0.3 g or more, from the viewpoint of measuring MgZn 2 (100) and Mg 2 Zn 11 (321) with high accuracy.
  • amount of the plating film to be scraped off is 0.1 g or more, preferably 0.3 g or more, from the viewpoint of measuring MgZn 2 (100) and Mg 2 Zn 11 (321) with high accuracy.
  • steel sheet components other than the plating film may be contained in the powder. However, these intermetallic compound phases are contained only in the plating film, and do not affect the above-mentioned peak intensity.
  • the plating film is powdered and subjected to X-ray diffraction because, when X-ray diffraction is performed on the plating film formed on the plated steel sheet, it is affected by the plane orientation of the plating film solidification structure, making it difficult to obtain a peak intensity corresponding to the amount of substance present.
  • the method for satisfying the above-mentioned relationship (1) and relationship (2) is not particularly limited.
  • the amount of MgZn2 and Mg2Zn11 (diffraction intensity of MgZn2(100) and Mg2Zn11 (321 )) can be controlled to be low by controlling the Mg content in the plating film to be low and reducing the ratio of the Mg content to the Zn content (for example, Mg / Zn to be 0.008 or less, preferably 0.006 or less).
  • the above relationships (1) and (2) can also be satisfied by controlling the Mg content in the plating film to a specific value and then adjusting the conditions for forming the plating film (e.g., cooling conditions after plating).
  • the plating film may further contain 0.01 to 3.0 mass% in total of one or more elements selected from B, Ca, Ti, V, Cr, Mn, Sr, Mo, In, Sn, Sb, Ce, and Bi. These elements have the effect of improving the stability of the corrosion products when the plating film corrodes, thereby delaying the progress of corrosion, and the effect of stabilizing the spangle size on the plating surface, thereby improving the surface appearance.
  • the coating weight of the plating film is preferably 45 to 120 g/ m2 per side.
  • the coating weight of the plating film is 45 g/ m2 or more, sufficient corrosion resistance is obtained for applications requiring long-term corrosion resistance, such as building materials, and when the coating weight of the plating film is 120 g/m2 or less , excellent corrosion resistance can be achieved while suppressing the occurrence of plating cracks during processing.
  • the coating weight of the plating film is more preferably 45 to 100 g/ m2 .
  • the coating weight of the plating film can be derived, for example, by a method in which a specific area of the plating film is dissolved and peeled off with a mixed solution of hydrochloric acid and hexamethylenetetramine as specified in JIS H 0401: 2013, and the coating weight is calculated from the difference in the weight of the steel sheet before and after peeling. To determine the coating weight per side using this method, the plating surface of the non-target side is sealed with tape so as not to be exposed, and then the above-mentioned dissolution is carried out.
  • the composition of the plating film can be confirmed by immersing the plating film in a hydrochloric acid solution or the like to dissolve it, and subjecting the solution to ICP emission spectrometry, atomic absorption spectrometry, etc.
  • This method is merely one example, and any method that can accurately quantify the composition of the plating film may be used, and is not particularly limited.
  • the plating film of the hot-dip Al-Zn plated steel sheet obtained by the present invention has a composition that is almost equivalent to that of the plating bath as a whole. Therefore, the composition of the plating film can be controlled with high precision by controlling the plating bath composition.
  • the base steel sheet constituting the hot-dip Al-Zn-plated steel sheet of the present invention is not particularly limited, and cold-rolled steel sheet, hot-rolled steel sheet, etc. can be used as appropriate depending on the required performance and standards.
  • the method for obtaining the base steel sheet is not particularly limited.
  • the hot-rolled steel sheet one that has been subjected to a hot rolling process and a pickling process can be used, and in the case of the cold-rolled steel sheet, it can be manufactured by further adding a cold rolling process.
  • the hot-dip Al-Zn plated steel sheet of the present invention has a plating film 20 formed on a base steel sheet 10, but an intermediate layer or a coating film can also be further formed on the plating film, if necessary.
  • the type of the coating film and the method for forming the coating film are not particularly limited and can be appropriately selected depending on the required performance.
  • the coating film can be formed by a method such as roll coater coating, curtain flow coating, spray coating, etc. After coating the coating material containing an organic resin, the coating film can be formed by heating and drying the coating film by means of hot air drying, infrared heating, induction heating, etc.
  • the intermediate layer is not particularly limited as long as it is a layer formed between the plating film of the hot-dip Al-Zn-plated steel sheet and the coating film.
  • examples include a chemical conversion coating film and a primer such as an adhesive layer.
  • the chemical conversion coating film can be formed, for example, by a chromate treatment or a chromium-free chemical conversion treatment in which a chromate treatment liquid or a chromium-free chemical conversion coating liquid is applied, and then dried at a steel sheet temperature of 80 to 300°C without rinsing with water.
  • These chemical conversion coating films may be single-layered or multi-layered, and in the case of multi-layered films, multiple chemical conversion treatments may be performed sequentially.
  • the method for producing a hot-dip Al-Zn plated steel sheet of the present invention is a method for producing a hot-dip Al-Zn plated steel sheet provided with a plating film.
  • the manufacturing method of the hot-dip Al-Zn-plated steel sheet of the present invention includes a step of forming the plating film on the base steel sheet using a plating bath containing 45-65 mass% Al, 1.0-3.0 mass% Si, with the remainder being Zn and unavoidable impurities, and in which the Mg content relative to the total mass of the plating bath is controlled to 0.3 mass% or less.
  • the step of forming the plating film is not particularly limited except for the plating bath conditions described below.
  • the steel sheet can be produced by cleaning, heating, and immersing the base steel sheet in a coating bath in a continuous hot-dip galvanizing facility.
  • recrystallization annealing or the like is performed to control the structure of the base steel sheet itself, and heating in a reducing atmosphere such as a nitrogen-hydrogen atmosphere is effective in preventing oxidation of the steel sheet and reducing a small amount of oxide film present on the surface.
  • the plating bath used in the process of forming the plating film contains 45-65 mass% Al and 1.0-3.0 mass% Si, with the remainder consisting of Zn and unavoidable impurities. As mentioned above, this is because the composition of the plating film as a whole is almost the same as the composition of the plating bath.
  • the method for producing a hot-dip Al-Zn coated steel sheet according to the present invention is characterized in that the Mg content relative to the total mass of the coating bath is controlled to 0.3 mass % or less.
  • Mg contained in the plating film may deteriorate the workability and corrosion resistance of the worked portion of the hot-dip Al-Zn plated steel sheet. Therefore, by appropriately controlling the contents of Al, Zn, and Si in the plating bath and reducing the Mg content, the deterioration of the workability and the corrosion resistance of the worked portion can be suppressed.
  • the Mg content in the plating bath must be controlled to 0.3 mass% or less, preferably 0.1 mass% or less, based on the total mass of the plating bath. If the Mg content in the plating bath is 0.3 mass% or less, the hot-dip Al-Zn-plated steel sheet produced can have sufficiently excellent workability and corrosion resistance at the processed part, and if it is 0.1 mass% or less, even better workability and corrosion resistance at the processed part can be realized. Thus, the lower the Mg content in the plating bath, the better the corrosion resistance of the hot-dip Al-Zn-plated steel sheet, so there is no particular lower limit for the Mg content. However, since it is technically difficult to make the Mg content in the plating bath completely 0.000 mass%, the lower limit of the Mg content in the plating is substantially about 0.001 mass%.
  • the means for reducing the Mg content in the coating bath is not particularly limited. For example, it is effective not to intentionally add Mg to the coating bath, or not to use pots or bath-immersed equipment used in the manufacture of coated steel sheets to which Mg is intentionally added, such as Zn-Al-Mg-based coated steel sheets or Al-Zn-Si-Mg-based coated steel sheets, in the manufacture of hot-dip Al-Zn-based coated steel sheets. This is because it is possible to prevent Mg-containing metal lumps adhering to the pots or bath-immersed equipment from dissolving and being mixed into the coating bath.
  • a metal block having a low Mg content among impurities as a raw material for the plating bath.
  • the temperature of the plating bath is not particularly limited, but is preferably in the range of (melting point + 20°C) to 650°C.
  • the reason why the lower limit of the bath temperature is set to the melting point + 20° C. is that the bath temperature needs to be equal to or higher than the solidification point in order to perform hot-dip plating, and by setting the temperature to the melting point + 20° C., solidification due to a local drop in the bath temperature of the plating bath is prevented.
  • the reason why the upper limit of the bath temperature is set to 650° C. is that if the bath temperature exceeds 650° C., rapid cooling of the plating film becomes difficult, and there is a risk that the interfacial alloy layer formed between the plating film and the steel sheet becomes thick.
  • the temperature of the base steel sheet immersed in the coating bath is not particularly limited, but it is preferable to control it to within ⁇ 20°C of the coating bath temperature in order to ensure the coating characteristics in the continuous hot-dip coating operation and to prevent changes in the bath temperature.
  • the immersion time of the base steel sheet in the plating bath is 0.5 seconds or more. This is because if it is less than 0.5 seconds, there is a risk that a sufficient plating film will not be formed on the surface of the base steel sheet.
  • the immersion time There is no particular upper limit to the immersion time, but since a longer immersion time may result in a thicker interfacial alloy layer being formed between the plating film and the steel sheet, it is more preferable to keep it within 8 seconds.
  • a heating temperature T which is a maximum temperature reached when reheating the steel sheet on which the plating film is formed, is set to 130 to 300°C, and after the heating, an average cooling rate C (°C/hr) from the heating temperature T (°C) to 100°C satisfies the following relationship (3): C ⁇ (T-100)/2...(3)
  • the solidification of the coating in the production of hot-dip Al-Zn coated steel sheets proceeds in a non-equilibrium state with a high cooling rate.
  • the ⁇ -Al phase in the coating contains supersaturated Zn, and the resulting hot-dip Al-Zn coating is hard and has low ductility.
  • the solid capacity of Zn in the ⁇ -Al phase is reduced in the hot-dip Al-Zn-based plated steel sheet that has been subjected to the heat treatment, softening the plated film and providing high ductility, which gives it excellent workability and corrosion resistance in the processed parts.
  • the heating temperature T is 130 to 300°C. If the heating temperature T is less than 130°C, the solid diffusion rate is low, so two-phase separation does not proceed sufficiently, and the plating film does not soften sufficiently. On the other hand, if the heating temperature T exceeds 300°C, the growth of the alloy phase at the interface between the base steel sheet and the plating film is promoted, which has a negative effect on workability. Therefore, the heating temperature T is set to a range of 130 to 300°C. From the same viewpoint, the heating temperature T is preferably 130 to 200°C.
  • the material is cooled so that the average cooling rate C (°C/hr) from the heating temperature T (°C) to 100°C satisfies the above relationship (3) in order to promote the two-phase separation of Al and Zn. Since solid diffusion of Al and Zn continues during the cooling process, the two-phase separation of Al and Zn can be effectively promoted by taking a sufficient cooling time to satisfy relationship (3). On the other hand, if the average cooling rate C (°C/hr) is greater than (T-100)/2, the two-phase separation of Al and Zn is insufficient, so the plating film does not soften sufficiently, and the workability and corrosion resistance of the processed parts cannot be satisfied.
  • the heat treatment for imparting the sound-absorbing heating and the subsequent heat retention can be carried out by a heating or heat retention device provided in or outside the continuous hot-dip plating equipment.
  • Continuous heating may be carried out in-line by providing a heating mechanism (e.g., induction heater, hot air stove, etc.) in the continuous hot-dip plating equipment, or batch heating may be carried out offline after winding into a coil.
  • Continuous heating may also be carried out by a heating mechanism (e.g., induction heater, hot air stove, etc.) in a continuous processing equipment outside the plating line.
  • the plated steel sheet that has been continuously heated in the plating line or in the continuous processing equipment may be wound into a coil and then appropriately heat-retained or heated.
  • a heat retention device may be provided to keep the plated film warm and slowly cool it during the cooling process after the hot-dip plated metal has solidified.
  • the type, shape, size, etc. of the heating or heat retention device there are no particular limitations on the type, shape, size, etc. of the heating or heat retention device, and the point is that it should be capable of giving the plated film the above-mentioned thermal history.
  • Examples 1 to 37 A cold-rolled steel sheet having a thickness of 0.8 mm produced by a conventional method was used as a base steel sheet, and annealing and plating were performed using a hot-dip plating simulator manufactured by Rhesca Corporation to produce hot-dip plated steel sheet samples 1 to 37 under the conditions shown in Table 1.
  • composition of the plating bath used in producing the hot-dip plated steel sheets was changed in various ranges within the ranges of Al: 0.2 to 70 mass%, Si: 0.0 to 3.2 mass%, B: 0.00 to 0.02 mass%, Ca: 0.0 to 1.0 mass%, Ti: 0.0 to 0.1 mass%, V: 0.1 to 0.1 mass%, Cr: 0.0 to 0.2 mass%, Mn: 0.0 to 0.1 mass%, Sr: 0.0 to 0.1 mass%, Mo: 0.0 to 0.1 mass%, In: 0.0 to 0.5 mass%, Sn: 0.0 to 0.1 mass%, Sb: 0.0 to 0.1 mass%, Ce: 0.0 to 1.0 mass%, and Bi: 0.00 to 0.05 mass% so as to obtain the composition of the plating film of each sample shown in Table 1.
  • the bath temperature of the coating bath was controlled to 460°C when Al was 0.2-5% by mass, 600°C when Al was 35-55% by mass, and 660°C when Al was over 60% by mass, so that the temperature of the base steel sheet entering the coating was the same as the coating bath temperature. Furthermore, when Al was 35-70% by mass, the coating process was carried out under the condition that the sheet temperature was cooled to a temperature range of 520-500°C in 3 seconds.
  • the coating weight of the plating film was controlled to be 85 ⁇ 5 g/ m2 per side for samples 1 to 34, 50 ⁇ 5 g/ m2 per side for sample 35, 100 ⁇ 5 g/ m2 per side for sample 36, and 125 ⁇ 5 g/ m2 per side for sample 37. Furthermore, after the above plating treatment, the samples 1 to 37, except for sample 16, were subjected to a predetermined thermal history (heating and cooling) in a heating furnace. The thermal history conditions are shown in Table 1.
  • Plating film composition, coating weight, X - ray diffraction intensity of MgZn2 and Mg2Zn11 .
  • a 100 mm diameter sample was punched out from each of the prepared plated steel sheets, the non-measurement surfaces were sealed with tape, and the plating was then dissolved and stripped off using a mixture of hydrochloric acid and hexamethylenetetramine as specified in JIS H 0401: 2013, and the adhesion weight of the plating film was calculated from the difference in mass of the sample before and after stripping.
  • the calculated adhesion weights of the plating film obtained are shown in Table 1.
  • the stripper solution was then filtered, and the filtrate and solid content were analyzed.
  • the filtrate was analyzed by ICP atomic emission spectroscopy to quantify the components other than insoluble Si.
  • the solids were dried and incinerated in a 650°C heating furnace, and then melted by adding sodium carbonate and sodium tetraborate.
  • the molten material was dissolved in hydrochloric acid, and the solution was analyzed by ICP emission spectroscopy to quantify the insoluble silicon.
  • the silicon concentration in the plating film was calculated by adding the soluble silicon concentration obtained by filtrate analysis to the insoluble silicon concentration obtained by solid content analysis.
  • the composition of the plating film obtained as a result of the calculation is shown in Table 1.
  • the measurement results are shown in Table 1.
  • Table 1 show that the samples of the present invention have a good balance of workability and corrosion resistance of the processed parts compared to the samples of the comparative examples.
  • the present invention provides a hot-dip Al-Zn-plated steel sheet and its manufacturing method that has reliable and stable excellent workability and corrosion resistance in the processed area.
  • Base steel sheet 20
  • Plating film 21
  • Main layer 22
  • Interface alloy layer 211
  • Dendrite 212
  • Interdendrite 212

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Abstract

Le but de la présente invention est de fournir une tôle d'acier revêtue dans laquelle l'adhésivité entre un film converti chimiquement et un film d'apprêt déposé est excellente, et qui présente une excellente résistance à la corrosion au niveau de parties traitées et de parties d'extrémité découpées.　Afin d'atteindre l'objectif, la présente invention est caractérisée en ce que : un film de placage a une composition contenant de 45 à 65 % en masse d'Al et de 1,0 à 3,0 % en masse de Si, la partie restante étant du Zn et des impuretés inévitables; la teneur en Mg par rapport à la masse totale du film de placage est de 0,3 % en masse ou moins; et l'intensité de diffraction du MgZn2 et Mg2Zn11 dans le film de placage tel que déterminé par diffraction des rayons X satisfait les relations (1) et (2). (1) : MgZn2 (100) = 0 (2) : Mg2Zn11 (321) = 0
PCT/JP2023/040988 2023-04-14 2023-11-14 TÔLE D'ACIER PLAQUÉE À BASE D'Al-Zn FONDU ET SON PROCÉDÉ DE FABRICATION Ceased WO2024214329A1 (fr)

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KR1020257032155A KR20250164208A (ko) 2023-04-14 2023-11-14 용융 Al-Zn계 도금 강판 및 그의 제조 방법
JP2024517175A JPWO2024214329A1 (fr) 2023-04-14 2023-11-14
CN202380097005.8A CN120917177A (zh) 2023-04-14 2023-11-14 热浸镀Al－Zn系钢板及其制造方法

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003213396A (ja) * 2002-01-18 2003-07-30 Jfe Engineering Kk 加工性と加工部耐食性に優れた表面処理鋼板及びその製造方法
WO2010082678A1 (fr) * 2009-01-16 2010-07-22 新日本製鐵株式会社 MATÉRIAU D'ACIER REVÊTU D'UN ALLIAGE Zn-Al-Mg-Si-Cr EN BAIN FONDU AYANT UNE EXCELLENTE RÉSISTANCE À LA CORROSION
WO2014119268A1 (fr) * 2013-01-31 2014-08-07 Ｊｆｅ鋼板株式会社 TÔLE EN ACIER GALVANISÉE À CHAUD DANS UN BAIN Al-Zn ET PROCÉDÉ DE PRODUCTION CORRESPONDANT
JP2022073969A (ja) * 2020-10-30 2022-05-17 Ｊｆｅスチール株式会社 溶融Ａｌ－Ｚｎ－Ｓｉ－Ｍｇ系めっき鋼板

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6128748A (ja) 1984-07-17 1986-02-08 Kubota Ltd エンジンの吸気通路への排気ガス還流装置
JP3617591B2 (ja) * 1997-11-07 2005-02-09 株式会社神戸製鋼所 Ｔｉｇ溶接方法及びｔｉｇ溶接材料
JP3811364B2 (ja) 2001-03-22 2006-08-16 Ｊｆｅスチール株式会社 加工性と加工部耐食性に優れた表面処理鋼板の製造方法
JP2004285387A (ja) 2003-03-20 2004-10-14 Nippon Steel Corp 外観に優れた溶融亜鉛めっき鋼板およびその製造方法
EP1930463B1 (fr) * 2005-09-01 2012-12-05 Nippon Steel Corporation PROCÉDÉ DE FABRICATION DE PRODUITS EN ACIER PLAQUE D UN ALLIAGE A BASE DE Zn-Al PAR IMMERSION A CHAUD PRÉSENTANT UNE EXCELLENTE APTITUDE A LA FLEXION
JP5101249B2 (ja) * 2006-11-10 2012-12-19 Ｊｆｅ鋼板株式会社 溶融Ｚｎ−Ａｌ系合金めっき鋼板およびその製造方法
WO2015052546A1 (fr) 2013-10-09 2015-04-16 ArcelorMittal Investigación y Desarrollo, S.L. Tôle à revêtement znaimg à flexibilité améliorée et procédé de réalisation correspondant
KR102325011B1 (ko) * 2019-12-20 2021-11-11 주식회사 포스코 무방향성 전기강판 및 그 제조방법
TW202142713A (zh) * 2020-04-23 2021-11-16 日商日本製鐵股份有限公司 熔融Al系鍍覆鋼板及熔融Al系鍍覆鋼板的製造方法
KR102237022B1 (ko) * 2020-08-07 2021-04-08 주식회사 포스코 연자성 철계 분말 및 그 제조방법, 연자성 부품

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003213396A (ja) * 2002-01-18 2003-07-30 Jfe Engineering Kk 加工性と加工部耐食性に優れた表面処理鋼板及びその製造方法
WO2010082678A1 (fr) * 2009-01-16 2010-07-22 新日本製鐵株式会社 MATÉRIAU D'ACIER REVÊTU D'UN ALLIAGE Zn-Al-Mg-Si-Cr EN BAIN FONDU AYANT UNE EXCELLENTE RÉSISTANCE À LA CORROSION
WO2014119268A1 (fr) * 2013-01-31 2014-08-07 Ｊｆｅ鋼板株式会社 TÔLE EN ACIER GALVANISÉE À CHAUD DANS UN BAIN Al-Zn ET PROCÉDÉ DE PRODUCTION CORRESPONDANT
JP2022073969A (ja) * 2020-10-30 2022-05-17 Ｊｆｅスチール株式会社 溶融Ａｌ－Ｚｎ－Ｓｉ－Ｍｇ系めっき鋼板

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