WO2022085434A1 - プレコート鋼板用めっき鋼板、プレコートめっき鋼板及び成形品 - Google Patents

プレコート鋼板用めっき鋼板、プレコートめっき鋼板及び成形品 Download PDF

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WO2022085434A1
WO2022085434A1 PCT/JP2021/036808 JP2021036808W WO2022085434A1 WO 2022085434 A1 WO2022085434 A1 WO 2022085434A1 JP 2021036808 W JP2021036808 W JP 2021036808W WO 2022085434 A1 WO2022085434 A1 WO 2022085434A1
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Prior art keywords
steel sheet
coating film
plating layer
plated steel
ratio
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PCT/JP2021/036808
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English (en)
French (fr)
Japanese (ja)
Inventor
博康 古川
隆志 藤井
史生 柴尾
明 中川
浩平 植田
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日本製鉄株式会社
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Priority to KR1020237015981A priority Critical patent/KR20230085182A/ko
Priority to AU2021363219A priority patent/AU2021363219B2/en
Priority to CN202180070332.5A priority patent/CN116529068A/zh
Priority to JP2022557388A priority patent/JP7401828B2/ja
Publication of WO2022085434A1 publication Critical patent/WO2022085434A1/ja

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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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/01—Layered products comprising a layer of metal all layers being exclusively metallic
    • 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
    • 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
    • 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
    • C23C2/04—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
    • 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
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals

Definitions

  • the present invention relates to plated steel sheets for pre-coated steel sheets, pre-coated plated steel sheets, and molded products.
  • the pre-coated galvanized steel sheet which is a pre-painted galvanized steel sheet, is required to have many performances such as corrosion resistance, moldability, coating hardness (scratch resistance), stain resistance, chemical resistance, and weather resistance.
  • performances such as corrosion resistance, moldability, coating hardness (scratch resistance), stain resistance, chemical resistance, and weather resistance.
  • the order of these required performances will differ depending on the application of the pre-coated galvanized steel sheet.
  • formability and corrosion resistance are particularly important among the above-mentioned performances.
  • Patent Document 1 discloses a pre-coated metal plate having excellent press formability, in which the coating film on the draw-molded portion is not damaged or peeled off by drawing.
  • the coating film in order to obtain a precoated metal plate having excellent press formability without peeling, the coating film has a specific viscoelastic curve, the number average molecular weight of the coating film resin is 10,000 or more, and the coating film has a coating film. It is disclosed that the glass transition point (Tg) of the resin is preferably 25 ° C. or higher.
  • Patent Document 2 discloses a pre-coated metal plate having excellent continuous press formability and excellent outdoor corrosion resistance at the end face portion of the drawn portion.
  • the Tg of the coating film is 40 to 120 ° C.
  • the coating film is measured by a dynamic viscoelasticity measuring device.
  • the minimum value of the storage elastic modulus in the rubber-like elastic region is 2 ⁇ 107 Pa or less
  • the surface tension of the coating film is 28 mN / m or less
  • the dynamic friction coefficient of the coating film surface is 0.15 or less. It is disclosed that it is important.
  • Patent Document 3 one or more coating layers are provided on one side or both sides of a metal plate, and the outermost coating film has a Tg of 5 to 30 ° C. and is at 23 ° C.
  • the universal hardness under a load of 5 mN is 2.5 N / mm 2 or more, the breaking elongation at 23 ° C is 100% or more, and the mirror gloss of the outermost coating film is the incident angle.
  • a high gloss precoated metal plate having a light receiving angle of 60% or more when measured under the condition of 60 ° is disclosed.
  • Patent Document 3 describes that a coated metal molded product having excellent press formability is provided, in which the gloss of the coating film is unlikely to decrease in the processed portion even if deep drawing is performed. There is.
  • the present inventors have conducted studies in order to further improve the formability and corrosion resistance of the pre-coated galvanized steel sheet as described above.
  • a phenomenon called coating film floating a phenomenon in which the coating film becomes rough due to aggregates of fine punctate swelling
  • the portion where these phenomena occur is referred to as a “coating film floating portion”.
  • Patent Document 1 defines the physical properties of a coating film and attempts to suppress buckling of the coating film due to compression strain of the draw-molded portion that occurs during drawing.
  • Patent Document 1 in order to suppress buckling of the coating film, in addition to the physical properties of the coating film, the hardness of the plating, the uniformity of the plating, the physical properties of the chemical conversion coating film, the processed shape, etc. Is presumed to be an influential factor that cannot be ignored.
  • Patent Document 1 does not contain any description regarding influencing factors other than the physical characteristics of the coating film. Therefore, there is still room for improvement in Patent Document 1 regarding the suppression of buckling of the coating film in the floating portion of the coating film generated by the drawing process, which the present inventors have focused on.
  • Patent Document 2 is not different from the invention of Patent Document 1 in that it defines the physical characteristics of the coating film and tries to suppress buckling of the coating film due to compression strain during drawing. Therefore, there is still room for improvement in Patent Document 2 regarding the suppression of buckling of the coating film in the floating portion of the coating film generated by the drawing process, which the present inventors have focused on.
  • Patent Document 3 Even in the technique of the above-mentioned Patent Document 3, the point that the buckling of the coating film due to the compression strain is suppressed only by defining the physical properties of the coating film is not different from the above-mentioned Patent Documents 1 and 2. Therefore, there is still room for improvement in Patent Document 3 regarding the suppression of buckling of the coating film in the floating portion of the coating film generated by the drawing process, which the present inventors have focused on.
  • the present invention has been made in view of the above problems, and an object of the present invention is to more reliably suppress the occurrence of floating portions of the coating film even when drawing is performed. It is an object of the present invention to provide a galvanized steel sheet for a pre-coated steel sheet, a pre-coated plated steel sheet, and a molded product.
  • the surface oxidation state of the plated steel sheet which is the coating original plate of the precoated plated steel sheet, is the coating film in the processed portion of the molded product. It was found that it affects the adhesion of.
  • the gist of the present invention completed as a result of further studies based on such findings is as follows.
  • the ratio of the magnesium oxide and the hydroxide is 2.0 or more with respect to the ratio of the metallic magnesium, and the zinc oxide and the zinc oxide and the ratio are
  • the ratio of aluminum oxide and hydroxide is 1.3 or more with respect to the ratio of metallic aluminum at a depth of 10 nm from the surface of the plating layer.
  • the plated steel plate according to any one of (1) to (4) has a chemical conversion treatment film located on the plating layer and a coating film located on the chemical conversion treatment film. At a depth of 10 nm from the interface between the chemical conversion coating and the plating layer toward the inside of the plating layer, the ratio of magnesium oxides and hydroxides to the ratio of metallic magnesium is 0.
  • the ratio of the oxide and hydroxide of the magnesium is relative to the ratio of the metallic magnesium.
  • the ratio of aluminum oxide and hydroxide is relative to the ratio of metallic aluminum.
  • the peel strength measured by cutting the interface between the chemical conversion coating film and the coating film by the SAICAS method is 1.00 kN / m or more on average and 20% or less of the cutting area is 20% or less of the cutting area.
  • a molded product in which the surface is peeled off and the remaining cutting area is in the form of coagulation failure in the coating film.
  • the molded product according to (8), wherein the plating layer in the molded product contains 5% or more and 15% or less of aluminum and 2% or more and 4% or less of magnesium.
  • a plated steel sheet for pre-coated steel sheets As described above, according to the present invention, a plated steel sheet for pre-coated steel sheets, a pre-coated plated steel sheet, and a molded product capable of more reliably suppressing the occurrence of floating portions of a coating film even when drawing is performed. It will be possible to provide.
  • the coating film is compressed due to the deformation (compression) of the plated steel sheet, and the excess coating film is moved upward. The appearance of peeling was observed.
  • the thickness of the plated steel sheet in this part was measured, it was larger than the thickness before molding. Therefore, it was clarified that the floating part of the coating film of interest was the compressed part of the plated steel sheet. ..
  • the portion where the coating film peeled off due to rubbing against the mold during the draw forming process that is, the portion where the coating film peeled off due to mechanical scratching
  • the coating film stretched following the original coating plate but were stretched.
  • the adhesion is reduced, and the part where the coating film peels off due to mold sliding (that is, the part where the peeling occurs due to stress concentration) is the plate of the plated steel plate.
  • the thickness was less than before molding. From these results, it was clarified that the portion where the coating film peeling occurred was the portion where the plated steel sheet was elongated.
  • the compression and elongation of the plated steel sheet do not occur independently but simultaneously, and the degree of compression and expansion differs depending on the processed portion.
  • the thickness of the plated steel sheet is increased as compared with that before forming.
  • the thickness of the plated steel sheet is smaller than that before molding.
  • adhesion strength peeling strength
  • the present inventors tend to cause the above-mentioned phenomenon of coating film floating in a pre-coated steel sheet using a galvanized steel sheet (particularly a galvanized alloy-plated steel sheet containing aluminum or magnesium) as a coating original plate. Focusing on the plated surface as a coating original plate as shown in (1) and (2) above, further studies were conducted.
  • the present inventors have found that the surface oxidation state of the plated steel sheet of the coated original plate affects the adhesion of the coating film in the molded portion.
  • the surface oxidation states of the plated steel sheet that the present inventors have focused on are (a) the states of aluminum, magnesium oxides and hydroxides on the surface of the plated steel sheet, and (b) the oxidation of zinc on the surface of the plated steel sheet.
  • the present inventors have diligently investigated the correlation between the oxidation state of the plating surface of the coated original plate and the adhesion of the coating film in the molded portion.
  • the abundance ratio of magnesium oxide and hydroxide at a depth of 10 nm below the surface of the plating layer is 2.
  • it was 0 or more it was clarified that good coating adhesion in the molded portion was obtained.
  • the surface concentration of magnesium surface oxide should be small, as described above, in magnesium near the surface of the plating layer, the ratio of oxide and hydroxide is constant with respect to the ratio of metal. It is not yet clear why it is better to do this.
  • the molding processing portion is used.
  • the ratio of aluminum and magnesium oxides and hydroxides at the interface between the plating layer and the chemical conversion coating should be lower than a certain level with respect to the metal ratio of these elements. It also became clear.
  • the zinc-based plated steel sheets containing aluminum and magnesium had a relative effect on the surface concentration of zinc due to the dissolution of aluminum and magnesium.
  • the zinc-based plated steel sheet as described above is subjected to chemical conversion treatment and coating to be a precoated steel sheet, in order to show good coating adhesion in the molded portion. It was also clarified that the ratio of zinc oxide and hydroxide at the interface between the plating layer and the chemical conversion treatment film should be higher than a certain level with respect to the ratio of metallic zinc.
  • the present inventors have applied a chemical conversion-treated film or a coating film (for example, a primer coating film when the coating film is composed of a plurality of layers) to a molded body obtained by molding the above-mentioned precoated plated steel sheet.
  • the peel strength and peeling morphology at the interface with the plating layer were examined.
  • the peeling strength of the coating film of the precoated steel sheet can be measured, but the peeling strength and the peeling form of the compressed portion and the extended portion of the plated steel sheet constituting the molded body cannot be accurately measured.
  • the present inventors evaluated the peel strength and the peeling morphology by using the SAICAS method (Surface and Interfacial Cutting Analysis System) as a method capable of simultaneously measuring these portions.
  • SAICAS method Surface and Interfacial Cutting Analysis System
  • the SAICAS method is a method of measuring the peel strength by cutting at an ultra-low speed from the sample surface to the adhesive interface between the substrate and the adherend using a sharp blade. Therefore, it is possible to observe the peel strength and the peeled state at the interface between specific layers of the laminated multilayer film, which was difficult to measure by the conventional method.
  • the peeling form of the coating film is a chemical conversion film or a coating film (for example, a plurality of layers of the coating film). In the case of rice field.
  • the interfacial peeling form refers to the cohesive destruction of the chemical conversion treatment film, the interfacial peeling between the chemical conversion treatment film and the coating film (for example, the primer coating film when the coating film is composed of a plurality of layers), or the chemical conversion treatment film. It refers to any of the interfacial peeling between the plating layer and the plating layer, or a composite form of these states.
  • the film thickness of the chemical conversion treatment film is extremely thin, it is integrated with the plating layer and the coating film (for example, when the coating film consists of a plurality of layers, the primer coating film), and the above peeling form can be visually distinguished. Can't be done.
  • the first embodiment of the present invention shown below is an embodiment focusing on the state of aluminum, magnesium oxides and hydroxides on the surface of the plated steel sheet referred to as (a) above.
  • the second embodiment of the present invention shown below is an embodiment focusing on the state of zinc oxides and hydroxides on the surface of the plated steel sheet referred to as (b) above.
  • the third embodiment of the present invention shown below is an embodiment focusing on the state of zinc, aluminum, magnesium oxides and hydroxides on the surface of the plated steel sheet.
  • the plated steel sheet 10 according to the present embodiment has a steel sheet 101 as a base material and a plating layer 103 located on one side of the steel sheet. Further, in the plated steel sheet 10 according to the present embodiment, as shown schematically in FIG. 1B, the plated layers 103 may be located on both sides of the steel sheet 101 as a base material.
  • various steel sheets can be used depending on the mechanical strength and the like required for the plated steel sheet 10.
  • Examples of such a steel sheet 101 include ultra-low carbon steel containing Al-killed steel, Ti, Nb and the like, and high-strength steel in which the ultra-low carbon steel further contains a reinforcing element such as P, Si and Mn.
  • Various steel sheets such as these can be mentioned.
  • the thickness of the steel sheet 101 according to the present embodiment may be appropriately set according to the mechanical strength and the like required for the plated steel sheet 10, for example, 0.2 mm to 2.0 mm. Can be a degree.
  • the plating layer 20 according to the present embodiment is a layer formed on at least one surface of the steel sheet 101, in order to improve the corrosion resistance of the plated steel sheet 10. It will be provided.
  • the chemical composition of the plating layer 103 according to the present embodiment will be described.
  • the plating layer 103 according to the present embodiment contains, in terms of mass%, aluminum (Al): 0.5% or more and 60.0% or less, magnesium (Mg): 0.5% or more and 15.0% or less, and The balance is a plating layer composed of zinc (Zn) and impurities. That is, the plating layer 103 according to the present embodiment is an Al—Mg—Zn-based ternary plating layer.
  • the Zn alloy plating layer 103 according to the present embodiment contains Al in an amount of 0.5% by mass or more and 60.0% by mass or less.
  • Al content By setting the Al content to 0.5% by mass or more and 60.0% by mass or less, the corrosion resistance of the plated steel sheet 10 according to the present embodiment is improved, and the adhesion of the plating layer 103 (more specifically, the steel sheet). Adhesion with 101) can be ensured.
  • the Al content is preferably 5.0% by mass or more.
  • the Al content exceeds 60.0% by mass, the effect of improving the corrosion resistance of the plated steel sheet 10 is saturated.
  • the Al content is preferably 15.0% by mass or less.
  • the plating layer 103 according to the present embodiment contains Mg in an amount of 0.5% by mass or more and 15.0% by mass or less.
  • Mg content By setting the Mg content to 0.5% by mass or more and 15.0% by mass or less, the corrosion resistance of the plated steel sheet 10 according to the present embodiment is improved, and the adhesion of the plating layer 103 (more specifically, the steel sheet). Adhesion with 101) can be ensured.
  • the content of Mg is preferably 2.0% by mass or more.
  • the Mg content exceeds 15.0% by mass, the plating layer 103 becomes brittle and the adhesion of the plating layer 103 deteriorates.
  • the Mg content is preferably 4.0% by mass or less.
  • the balance other than the above components is Zn and impurities.
  • silicon (Si) may be contained in a content of 0% by mass or more and 2.0% by mass or less instead of a part of Zn in the balance.
  • the plating layer 103 may contain Si in an amount of 0% by mass or more and 2.0% by mass or less instead of a part of the remaining Zn.
  • Si content By setting the Si content to 0% by mass or more and 2.0% by mass or less, it is possible to more reliably ensure the adhesion of the plating layer 103.
  • the Si content exceeds 2.0% by mass, the effect of improving the adhesion of the plating layer 103 may be saturated.
  • the Si content is more preferably 1.6% by mass or less.
  • elements such as Fe, Sb, and Pb may be contained alone or in combination in an amount of 1% by mass or less instead of a part of Zn in the balance.
  • the plated steel sheet 10 for a precoated steel sheet provided with the plating layer 103 having the above chemical components for example, a plated steel sheet having a Zn-11% Al-3% Mg-0.2% Si alloy plating layer.
  • Fused zinc-aluminum-magnesium-silicon alloy plated steel sheet for example, "Super Dyma (registered trademark)", “ZAM (registered trademark)” manufactured by Nippon Steel Co., Ltd.
  • Super Dyma registered trademark
  • ZAM registered trademark
  • the average film thickness of the plated layer 103 is preferably, for example, 6 ⁇ m or more, and more preferably 9 ⁇ m or more. ..
  • the average film thickness d1 of the plating layer 103 exceeds 45 ⁇ m, the influence of the increase in plating cost becomes larger than the corrosion resistance improvement allowance. Therefore, from the viewpoint of economy, the average film thickness d1 of the plating layer 103 is preferably 45 ⁇ m or less.
  • the average film thickness d1 of the plating layer 103 can be calculated by, for example, the following weight method. That is, a plated steel sheet having a predetermined area (for example, 50 mm ⁇ 50 mm) is dissolved in hydrochloric acid containing an inhibitor, and the dissolved weight is calculated by the weight difference before and after the dissolution. The element weight ratio of Al, Zn, Fe, etc. contained in the solution is separately measured and calculated by high frequency inductively coupled plasma (ICP) emission spectroscopy, and the average specific gravity of the plating layer is calculated from the ratio. .. The average film thickness d1 of the plating layer 103 is calculated by dividing the melted weight by the average specific gravity and further dividing by the area (or, in the case of double-sided plating, the area ⁇ 2).
  • ICP inductively coupled plasma
  • the plating layer 103 defines the states of metals, oxides and hydroxides of magnesium and aluminum on the surface of the plating layer 103.
  • XPS X-ray Photoelectron Spectroscopy
  • Quantum2000 type manufactured by ULVAC-PHI is used.
  • X-ray source Al K ⁇
  • X-ray output 15 kV, 25 W
  • measurement area 300 ⁇ 300 ⁇ m square
  • vacuum degree 1.5 ⁇ 10-9 Torr (1 Torr is , Approximately 133.3 Pa.)
  • Detection accuracy 45 o .
  • the sputtering for depth profile analysis is ion species: Ar + , acceleration voltage: 1 kV, region: 1 ⁇ 1 mm, and sputtering rate: 2.7 nm / min (SiO 2 conversion). Sputtering is performed based on the above sputtering rate, and the position specified by such sputtering is regarded as the above "position A".
  • the attribution separation of the ratio (presence ratio) of magnesium oxide and hydroxide to metallic magnesium is determined from the narrow spectrum in the region of 295 to 325 cm -1 by Mg KLL, for each substance (oxide, water). Calculated from the intensity ratio of peaks attributed to oxides and metals).
  • the attribution separation of the ratio (presence ratio) of aluminum oxide and hydroxide to metallic aluminum is determined from the narrow spectrum in the region of 68 to 84 cm -1 by Al 2p, for each substance (oxide, water). Calculated from the intensity ratio of peaks attributed to oxides and metals).
  • the ratio of magnesium oxide and hydroxide at a depth of 10 nm from the surface of the plating layer (position A in FIG. 2) specified as described above is a metal. It is 2.0 or more with respect to the ratio of magnesium.
  • the abundance ratio of the oxide and the hydroxide of magnesium to the metallic magnesium is 2.0 or more, the precoated plated steel sheet using the plated steel sheet 10 for the precoated steel sheet having the plating layer 103 according to the present embodiment is squeezed. Even when processed, good coating adhesion in the molded portion is realized, and it is possible to suppress the occurrence of the coating floating portion.
  • the abundance ratio of magnesium oxides and hydroxides to such metallic magnesium is preferably 4.0 or more, and more preferably 6.0 or more. Further, the upper limit of the abundance ratio of magnesium oxides and hydroxides to metallic magnesium is substantially 10.0.
  • the ratio of the aluminum oxide and the hydroxide at the depth of 10 nm from the surface of the plating layer (position A in FIG. 2) specified as described above is , It is preferable that it is 1.3 or more with respect to the ratio of metallic aluminum.
  • the pre-coated plated steel sheet using the plated steel sheet 10 having the plating layer 103 according to the present embodiment is drawn because the abundance ratio of aluminum oxides and hydroxides to metallic aluminum is 1.3 or more. Even so, better coating adhesion in the molded portion can be realized, and the occurrence of the coating floating portion can be suppressed more reliably.
  • the abundance ratio of the aluminum oxide and hydroxide is less than 1.3, it may not be possible to develop better coating film adhesion in the molded portion.
  • the abundance ratio of aluminum oxides and hydroxides to such metallic aluminum is more preferably 1.4 or more, still more preferably 2.0 or more. Further, the upper limit of the abundance ratio of aluminum oxides and hydroxides to metallic aluminum is substantially 10.0.
  • the measurement by XPS is carried out for a region having a size of 300 ⁇ m ⁇ 300 ⁇ m.
  • the abundance ratio calculated as described above means a value as an average in the measurement region as described above.
  • the plated steel sheet 10 it is possible to develop good coating film adhesion in the molded portion as long as the above relationship regarding magnesium is established in the plated layer 103. This is because magnesium has a lower standard electrode potential than aluminum, so that corrosion easily progresses, and it is effective to further suppress the corrosion of magnesium to improve the adhesion of the coating film in the molded portion. ..
  • the plated steel sheet 10 for precoated steel sheet according to the present embodiment has been described in detail with reference to FIGS. 1A to 2.
  • the plated steel sheet 10 for a precoated steel sheet according to the present embodiment as described above can be manufactured, for example, as follows. First, the surface of the prepared steel sheet 101 is subjected to pretreatment such as cleaning and degreasing as necessary. After that, a plating layer is formed by applying a usual non-oxidizing furnace type hot-dip plating method to the steel sheet 101 which has been pretreated as necessary.
  • a post-treatment step of at least one of acid treatment, alkali treatment, and mechanical cutting treatment is carried out on the steel sheet on which the plating layer is formed. This modifies the surface of the plating layer or removes the surface of the plating layer to satisfy the conditions relating to the XPS spectrum previously mentioned.
  • a hot-dip galvanizing bath having a desired chemical component that is, Al: 0.5 to 60.0% by mass, Mg: 0.5 to 15.0% by mass
  • the balance is Zn and
  • a hot-dip galvanizing bath made of impurities is prepared, and the bath temperature of the plating bath is controlled to about 450 ° C.
  • the obtained steel sheet 101 is immersed in a plating bath, and hot-dip galvanizing is adhered to the surface of the steel sheet so as to have a desired average film thickness.
  • the cooling rate after plating is controlled to 10 ° C./sec or more. This makes it possible to form a plating layer.
  • the plating layer obtained as described above various methods such as acid treatment, alkali treatment, and mechanical cutting treatment are performed while measuring the XPS spectrum with the XPS analyzer set under the measurement conditions as described above.
  • the surface of the plating layer is modified or removed until the conditions relating to the XPS spectrum mentioned above are satisfied.
  • the plated steel sheet 10 for a precoated steel sheet according to the present embodiment which has the plating layer 103 as described above, can be manufactured.
  • any of the alkaline treatment, the acid treatment, and the mechanical cutting treatment to be applied may be used, and various combinations of these treatments may be used.
  • the higher the alkali concentration and the longer the treatment time the higher the abundance ratio of magnesium oxides and hydroxides on the surface of the plating layer tends to be.
  • the spraying time is about 10 seconds or less, the magnesium on the surface of the plating layer is oxidized.
  • the abundance ratio of the substance and the hydroxide cannot satisfy the specified condition, but if the spraying time is lengthened, the condition is satisfied, and if the spraying time is lengthened to about 2 minutes, the condition is surely satisfied.
  • this degreasing solution is doubled, the condition is surely satisfied in about 30 seconds.
  • the metallic magnesium component is dissolved by the alkali treatment, changed to an oxide or a hydroxide, and re-deposited on the plating surface.
  • the specified conditions can be obtained by treating under weak conditions such as removing the dirt component adhering to the plating surface.
  • the spraying time is set to about 5 to 10 seconds, and the abundance ratio of magnesium oxide and hydroxide on the surface of the plating layer is a specified condition. Can be met. However, if sprayed for a longer period of time, the conditions will not be met.
  • a mechanical cutting treatment when a mechanical cutting treatment is performed, such treatment has an effect of removing all of metallic magnesium, oxides and hydroxides on the surface of the plating layer. Therefore, it is preferable to use a nylon brush, a grindstone having an appropriate particle size, or the like to perform the treatment under a weak condition that removes the dirt component adhering to the plating surface. After the mechanical cutting process, wash with water to remove cutting stains.
  • the conditions of each treatment also change depending on the initial oxidation state of the plating layer of the steel sheet to be used. Therefore, the plated steel sheet 10 for a precoated steel sheet according to the present embodiment may be manufactured by appropriately selecting the optimum conditions.
  • the precoated plated steel sheet 20 uses the plated steel sheet 10 for precoated steel sheet as described above as the base material.
  • the pre-coated plated steel sheet 20 includes a steel sheet 101, a plating layer 201 located on one side of the steel sheet 101, a chemical conversion coating film 203 located on the plating layer 201, and a coating film 205 located on the chemical conversion coating film 203. have.
  • the plating layer 201, the chemical conversion coating film 203, and the coating film 205 may be formed on both surfaces of the steel sheet 101.
  • the steel plate 101 in the pre-coated plated steel sheet 20 according to the present embodiment has the same configuration as the steel plate 101 in the pre-coated steel plate for pre-coated steel sheet 10 described above, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the plating layer 201 of the precoated plated steel sheet 20 with the formation of the chemical conversion treatment film 203 described later, in the vicinity of the interface between the plating layer 201 and the chemical conversion treatment film 203, atoms and the like contained in each layer may be present. Mutual diffusion and the like may occur.
  • the average chemical composition of the plating layer 201 is the same as that of the plating layer 103 in the plated steel sheet 10 for precoated steel sheets described above, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the chemical conversion treatment film 203 is a film layer located on the plating layer 201, and is known for degreasing steps and cleaning of impurities such as oil and surface oxides adhering to the surface of the plated steel sheet 10 for precoated steel sheets. A layer formed by chemical conversion treatment after being removed in the process.
  • the chemical conversion coating 203 is selected from the group consisting of a resin, a silane coupling agent, a zirconium compound, silica, phosphoric acid and a salt thereof, a fluoride, a vanadium compound, and tannin or tannic acid. It may contain one or more. By containing these substances, the film forming property after application of the chemical conversion treatment liquid, the barrier property (denseness) of the film against corrosive factors such as moisture and corrosive ions, and the film adhesion to the plated surface are further improved. It improves and contributes to raising the corrosion resistance of the film.
  • the chemical conversion treatment film 203 contains any one or more of a silane coupling agent or a zirconium compound, a crosslinked structure is formed in the film 203 to strengthen the bond with the plating surface. As a result, it is possible to further improve the adhesion and barrier property of the film.
  • the chemical conversion coating film 203 contains any one or more of silica, phosphoric acid and a salt thereof, fluoride, or a vanadium compound, these compounds function as an inhibitor to form a precipitation film on the plating or steel surface. Form a passivation film. As a result, it becomes possible to further improve the corrosion resistance.
  • the resin known organic resins such as polyester resin, polyurethane resin, epoxy resin, phenol resin, acrylic resin, and polyolefin resin can be used.
  • the resins polyester resin, urethane resin, epoxy resin, acrylic resin, etc.
  • the resin may be used alone or in combination of two or more.
  • the content of the resin in the chemical conversion-treated film 203 is preferably, for example, 0% by mass or more and 85% by mass or less with respect to the solid content of the film.
  • the content of the resin is more preferably 0% by mass or more and 60% by mass or less, and further preferably 1% by mass or more and 40% by mass or less. If the resin content exceeds 85% by mass, the proportion of other film constituents may decrease, and the performance required for a film other than corrosion resistance may decrease.
  • silane coupling agent examples include ⁇ - (2-aminoethyl) aminopropyltrimethoxysilane, ⁇ - (2-aminoethyl) aminopropylmethyldimethoxysilane, and ⁇ - (2-aminoethyl) aminopropyltriethoxysilane.
  • the amount of the silane coupling agent added to the chemical conversion treatment agent for forming the chemical conversion treatment film 203 can be, for example, 2 to 80 g / L. If the amount of the silane coupling agent added is less than 2 g / L, the adhesion to the plating surface may be insufficient, and the processing adhesion of the coating film may be lowered. Further, when the addition amount of the silane coupling agent exceeds 80 g / L, the cohesive force of the chemical conversion treatment film may be insufficient, and the processing adhesion of the coating film may be lowered.
  • the silane coupling agent as exemplified above may be used alone or in combination of two or more.
  • zirconium compound examples include zirconium normal propylate, zirconium normal butyrate, zirconium tetraacetyl acetonate, zirconium monoacetyl acetonate, zirconium bisacetyl acetonate, zirconium monoethyl acetoacetate, zirconium acetyl acetonate bisethyl acetoacetate, and the like.
  • the amount of the zirconium compound added in the chemical conversion treatment agent for forming the chemical conversion treatment film 203 can be, for example, 2 to 80 g / L. If the amount of the zirconium compound added is less than 2 g / L, the adhesion to the plating surface may be insufficient, and the processing adhesion of the coating film may be lowered. Further, when the addition amount of the zirconium compound exceeds 80 g / L, the cohesive force of the chemical conversion treatment film may be insufficient, and the processing adhesion of the coating film may be lowered. Such a zirconium compound may be used alone or in combination of two or more.
  • silica for example, "Snowtex N”, “Snowtex C”, “Snowtex UP”, “Snowtex PS” manufactured by Nissan Chemical Industries, Ltd., “Adelite AT-20Q” manufactured by ADEKA, etc. are commercially available. Silica gel or powdered silica such as Aerosil # 300 manufactured by Nippon Aerosil Co., Ltd. can be used. Silica can be appropriately selected depending on the required performance of the pre-coated galvanized steel sheet. The amount of silica added in the chemical conversion treatment agent for forming the chemical conversion treatment film 203 is preferably 1 to 40 g / L.
  • the amount of silica added is less than 1 g / L, the processing adhesion of the coating film may decrease, and when the amount of silica added exceeds 40 g / L, the effects of processing adhesion and corrosion resistance are obtained. Is uneconomical because it is likely to saturate.
  • phosphoric acid and its salts examples include phosphoric acids such as orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid and tetraphosphoric acid, salts thereof, and ammonium salts such as triammonium phosphate and diammonium hydrogenphosphate.
  • Phosphoric acids such as aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid) and their salts, organic phosphoric acids such as phytic acid. And their salts and the like.
  • Examples of the phosphoric acid salt include metal salts with Na, Mg, Al, K, Ca, Mn, Ni, Zn, Fe and the like as salts other than the ammonium salt. Phosphoric acid and its salt may be used alone or in combination of two or more.
  • the content of phosphoric acid and its salt is preferably 0% by mass or more and 20% by mass or less with respect to the film solid content. If the content of phosphoric acid and its salt exceeds 20% by mass, the film may become brittle and the process adhesion of the film when forming the precoated plated steel sheet may decrease.
  • the content of phosphoric acid and its salt is more preferably 1% by mass or more and 10% by mass or less.
  • fluoride examples include zircon fluoride ammonium, silica fluoride ammonium, titanium fluoride ammonium fluoride, sodium fluoride, potassium fluoride, calcium fluoride, lithium fluoride, titanium hydrofluoric acid, zircon hydrofluoric acid and the like. .. Such fluoride may be used alone or in combination of two or more.
  • the fluoride content is preferably 0% by mass or more and 20% by mass or less with respect to the film solid content. If the fluoride content exceeds 20% by mass, the film may become brittle and the process adhesion of the film during molding of the precoated plated steel sheet may decrease.
  • the fluoride content is more preferably 1% by mass or more and 10% by mass or less.
  • vanadium compound examples include vanadium compounds obtained by reducing pentavalent vanadium compounds such as vanadium pentoxide, metavanadic acid, ammonium metavanadate, sodium metavanadate, and vanadium oxytrichloride to 2 to 4 valences with a reducing agent, and vanadium trioxide. , Vanadium dioxide, vanadium oxysulfate, vanadium oxyhydrate, vanadium oxyacetylacetonate, vanadium acetylacetonate, vanadium trichloride, limbanadomolybdic acid, vanadium sulfate, vanadium dichloride, vanadium oxide, etc. Examples include vanadium compounds. Such vanadium compounds may be used alone or in combination of two or more.
  • the content of the vanadium compound is preferably 0% by mass or more and 20% by mass or less with respect to the solid content of the film. If the content of the vanadium compound exceeds 20% by mass, the film may become brittle and the process adhesion of the film when forming the precoated plated steel sheet may decrease.
  • the content of the vanadium compound is more preferably 1% by mass or more and 10% by mass or less.
  • tannin or tannic acid either hydrolyzable tannin or condensed tannin can be used.
  • tannins and tannic acids include hamameta tannins, quintuplet tannins, gall apple tannins, milovalan tannins, jibijibi tannins, algarovilla tannins, baronia tannins, catechins and the like.
  • the amount of tannin or tannic acid added in the chemical conversion treatment agent for forming the chemical conversion treatment film 203 can be 2 to 80 g / L. If the amount of tannin or tannic acid added is less than 2 g / L, the adhesion to the plating surface may be insufficient, and the processing adhesion of the coating film may be lowered. Further, when the amount of tannin or tannic acid added exceeds 80 g / L, the cohesive force of the chemical conversion-treated film, which lacks processing adhesion, may be insufficient, and the processing adhesion of the coating film may decrease. be.
  • an acid, an alkali or the like may be added to the chemical conversion treatment agent for forming the chemical conversion treatment film 203 for pH adjustment within a range in which the performance is not impaired.
  • the chemical conversion treatment agent containing various components as described above is applied on one or both sides of the plated steel sheet 10 for precoated steel sheets and then dried to form the chemical conversion treatment film 203.
  • a chemical conversion treatment film of 10 to 1000 mg / m 2 per side on the plated steel sheet for precoated steel sheet.
  • the adhesion amount of the chemical conversion coating film 203 is more preferably 20 to 800 mg / m 2 , and most preferably 50 to 600 mg / m 2 .
  • the film thickness of the chemical conversion coating film 203 corresponding to the amount of adhesion (thickness d2 in FIGS. 3A and 3B) is approximately 0.01 to 1 ⁇ m, although it depends on the components contained in the chemical conversion treatment agent.
  • the coating film 205 is a layer formed on the chemical conversion treatment film 203 as described above.
  • the coating film 205 may be composed of a single layer as schematically shown in FIGS. 3A and 3B, or may be composed of a plurality of two or more layers.
  • the coating film in contact with the chemical conversion treatment film 203 is also called a primer coating film, and the entire coating film 205 and the chemical conversion treatment film 203 are used. It is often provided for the purpose of ensuring adhesion and corrosion resistance.
  • the coating film located above the primer coating film is also called a top coating film, and is often provided for the purpose of ensuring the design property, barrier property, and other surface functionality by coloring.
  • the coating film 205 is composed of a single layer, the coating film 205 is often provided so as to exhibit at least one of the functions exhibited by the above-mentioned primer coating film and the top coating film.
  • the coating film 205 contains at least a resin. Further, it is preferable that the coating film 205 further contains a pigment. In addition to these components, the coating film 205 may contain various additives such as a leveling agent, a defoaming agent, a colorant, a viscosity modifier, and an ultraviolet absorber.
  • the coating liquid for forming the coating film 205 is preferably obtained by dispersing or dissolving each of the above components in a solvent.
  • the coating film 205 is composed of a primer coating film and a top coating film.
  • a case where the coating film 205 is composed of a primer coating film and a top coating film will be taken as an example in detail.
  • a top coating film will be taken as an example in detail.
  • the base paint of the primer coating film an appropriate one may be selected according to the usage environment and application of the precoated plated steel sheet.
  • the type of resin for the base paint generally known ones can be used. Examples of such resins include polyacrylic resins, polyolefin resins, polyurethane resins, epoxy resins, polyester resins, polybutyral resins, melamine resins, silicon resins, fluororesins, acrylic resins and the like. These resins can be used as they are or in combination. Further, these resins can be cured with any curing agent.
  • the base paint can be used in any form such as an organic solvent type, a water type, or a powder type.
  • the base paint preferably contains a rust preventive pigment, and more preferably contains a chromate-free rust preventive pigment.
  • Chromate-free rust preventive pigments in the base paint include calcium ion-exchange silica (commonly known as calcium silicate), aluminum tripolyphosphate, phosphorus vanadium pigment (PV pigment), zinc phosphate, iron phosphate, etc.
  • Aluminum phosphate, calcium molybdenate, aluminum molybdenate, barium molybdate, vanadium oxide, water-dispersed silica, fumed silica, orthophosphoric acid, pyrophosphoric acid, metaphosphoric acid, hypophosphoric acid, phosphoric acid, hypophosphoric acid and these. Phosphoric acid etc. can be used.
  • the content of the rust preventive pigment is preferably, for example, 5 to 70% by mass with respect to the solid content of the coating film.
  • the content of the rust-preventive pigment is less than 5% by mass, it may not be possible to sufficiently guarantee the curing of the corrosion resistance, and the rigidity and cohesive force of the coating film are lowered, so that the coating film is plated.
  • the coating film peeling that is, the coating film biting as physical peeling
  • the content of the rust preventive pigment exceeds 70% by mass, the processability may be deteriorated.
  • the content of the rust preventive pigment is more preferably 15 to 70% by mass, further preferably 20 to 50% by mass.
  • the curing agent it is preferable to use an amino resin such as a melamine resin, a urea resin or a benzoguanamine resin, or an isocinate compound and a block thereof.
  • the mass ratio of the curing agent to the resin in the dry coating film is preferably 5 to 30 parts by mass with respect to 100 parts by mass of the total amount of the resin and the curing agent. If the amount of the curing agent is 5 parts by mass or less, the adhesiveness and corrosion resistance may not be sufficiently exhibited, and if it is 30 parts by mass or more, the processability and chemical resistance may be deteriorated. be.
  • pre-coated galvanized steel sheets pre-coated galvanized steel sheets to have a primer coating film thickness of 2 ⁇ m or more and 10 ⁇ m or more before molding.
  • the film thickness of the primer coating film is preferably 2 to 10 ⁇ m.
  • the film thickness of the primer coating film is less than 2 ⁇ m, there is a possibility that the functions such as corrosion resistance required for the precoated plated steel sheet cannot be sufficiently exhibited.
  • the film thickness of the primer coating film exceeds 10 ⁇ m, the processability of the coating film may deteriorate.
  • the primer coating composition containing the components constituting the primer coating film as described above After applying the primer coating composition containing the components constituting the primer coating film as described above, it is baked at a temperature of 150 ° C. or higher and lower than 300 ° C., and cured and dried. If the baking temperature is less than 150 ° C, the adhesion may not be sufficiently ensured, and if the baking temperature is 300 ° C or higher, the resin component may be thermally deteriorated and the workability may be deteriorated. There is sex.
  • the primer coating composition as described above can be applied by a generally known coating method, for example, roll coating, curtain flow coating, air spray, airless spray, dipping, bar coating, brush coating and the like.
  • the base paint of the top coating film an appropriate one may be selected according to the usage environment and application of the precoated plated steel sheet.
  • the type of resin for the base paint generally known ones can be used. Examples of such resins include polyacrylic resins, polyolefin resins, polyurethane resins, epoxy resins, polyester resins, polybutyral resins, melamine resins, silicon resins, fluororesins, acrylic resins and the like. These resins can be used as they are or in combination. Further, these resins can be cured with any curing agent.
  • the base paint can be used in any form such as an organic solvent type, a water type, or a powder type.
  • the resin contained in the base coating film of the top coating film may be the same as or different from the resin contained in the base coating film of the primer coating film. However, considering the adhesion between the primer coating film and the top coating film, it is preferable to use the same kind of coating film.
  • the base paint preferably contains a high molecular weight polyester resin and a curing agent for applications with more severe molding processability.
  • the polymer polyester resin can be selected according to the use of the precoated galvanized steel sheet, and any polymer polyester resin usually used as a solvent-based paint can be used.
  • the polymer polyester resin is preferably a polymer polyester resin whose main resin is composed of ester bonds of two or more kinds of resin monomers.
  • an amino resin such as a melamine resin, a urea resin or a benzoguanamine resin, or an isocinate compound and a block thereof are used. be able to.
  • the mass ratio of the curing agent to the resin in the dry coating film is preferably 10 to 35 parts by mass with respect to 100 parts by mass of the total amount of the resin and the curing agent. If the amount of the curing agent is less than 10 parts by mass, adhesion, corrosion resistance, solvent resistance, etc. may not be sufficiently guaranteed, and if it exceeds 35 parts by mass, workability, chemical resistance, impact resistance, etc. may not be sufficiently ensured. May be less sexual.
  • the top coating film further contains, if necessary, pigments, surface-modified metal powders and glass powders, dispersants, leveling agents, waxes, aggregates, additives such as fluororesin beads, and diluting solvents. be able to.
  • the film thickness of the top coating film before molding is preferably in the range of, for example, 5 to 25 ⁇ m.
  • the total film thickness is preferably in the range of 5 to 25 ⁇ m.
  • the paint composition of the top coating film After applying the paint composition of the top coating film, it is baked at a temperature of 150 ° C or higher and lower than 300 ° C, and cured and dried. If the baking temperature is less than 150 ° C, the adhesion of each coating film may not be sufficiently guaranteed, and if the baking temperature is 300 ° C or higher, the resin components such as the polyester resin component may not be sufficiently adhered. Thermal deterioration may occur and workability may decrease.
  • the top paint can be applied by a generally known application method, for example, roll coat, curtain flow coat, air spray, airless spray, dipping, bar coat, brush coating and the like.
  • the chemical conversion treatment film, the primer coating film, and the top coating film according to the present embodiment have been described above with reference to the chemical conversion treatment agent and the coating composition used to form the respective films.
  • these components and the component composition of the formed film are usually different.
  • the composition of the chemical conversion treatment agent and the chemical conversion treatment film after coating are different due to the reaction with the plated steel sheet, the volatilization of volatile components in the chemical conversion treatment agent, etc. Identifying the composition of the coating layer is usually technically difficult. Further, it is technically difficult to specify the composition of such a chemical conversion-treated film layer by instrumental analysis or the like. This also applies to the primer coating film and the top coating film. Therefore, in the present embodiment, the chemical conversion treatment film, the primer coating film, and the top coating film to be formed are specified by specifying the composition of the chemical conversion treatment agent and the coating composition.
  • the metal, oxide and oxide of magnesium and aluminum at the interface of the plating layer 201 (more specifically, the interface between the plating layer 201 and the chemical conversion coating 203). Defines the state of hydroxide.
  • the “position B” located at a depth of 10 nm from the interface between the plating layer 201 and the chemical conversion coating film 203 toward the inside of the plating layer 201.
  • the states of metals, oxides, and hydroxides of magnesium and aluminum are specified, and the states of these substances at the interface of the plating layer 201 are used.
  • the position of the interface between the plating layer 201 and the chemical conversion coating film 203 can be specified from the element profile in the depth direction of the precoated plated steel sheet obtained by analyzing the precoated plated steel sheet by XPS. That is, in the present embodiment, the element contained in the chemical conversion treatment film 203 is used as a marker, and the place where the strength of the marker element is halved in the depth direction is defined as the interface between the plating layer 201 and the chemical conversion treatment film 203. ..
  • the measurement conditions for XPS for depth profile analysis and the measurement conditions for state analysis of metals, oxides, and hydroxides of magnesium and aluminum are the XPS in the galvanized steel sheet 10 for precoated steel sheet shown above. It is the same as the measurement condition of.
  • the state analysis of metals, oxides and hydroxides of magnesium and aluminum is specified by XPS.
  • Quantum2000 type manufactured by ULVAC-PHI is used, X-ray source: Al K ⁇ , X-ray output 15 kV, 25 W, measurement area: 300 ⁇ 300 ⁇ m square, vacuum degree: 1.5 ⁇ 10-9 Torr, detection accuracy. : 45 o .
  • the sputtering for depth profile analysis is ion species: Ar + , acceleration voltage: 1 kV, region: 1 ⁇ 1 mm, and sputtering rate: 2.7 nm / min (SiO 2 conversion). Sputtering is performed based on the above sputtering rate, and the position specified by such sputtering is regarded as the above "position B".
  • the attribution separation of the ratio (presence ratio) of magnesium oxide and hydroxide to metallic magnesium is determined from the narrow spectrum in the region of 295 to 325 cm -1 by Mg KLL, for each substance (oxide, water). Calculated from the intensity ratio of peaks attributed to oxides and metals).
  • the attribution separation of the ratio (presence ratio) of aluminum oxide and hydroxide to metallic aluminum is determined from the narrow spectrum in the region of 68 to 84 cm -1 by Al 2p, for each substance (oxide, water). Calculated from the intensity ratio of peaks attributed to oxides and metals).
  • the ratio of magnesium oxide and hydroxide at a depth of 10 nm (position B in FIG. 4) from the interface of the plating layer specified as described above is , It is 0.30 or less with respect to the ratio of metallic magnesium. Since the abundance ratio of magnesium oxides and hydroxides to metallic magnesium is 0.30 or less, even when the precoated galvanized steel sheet 20 according to the present embodiment is drawn, it is good in the molded portion. Excellent adhesion to the coating film is realized, and it is possible to suppress the occurrence of floating portions of the coating film.
  • the abundance ratio of magnesium oxides and hydroxides to such metallic magnesium is preferably 0.25 or less, and more preferably 0.20 or less. Further, the lower limit of the abundance ratio of magnesium oxides and hydroxides to metallic magnesium is substantially 0.01.
  • the interface of the plating layer 201 aluminum oxides and hydroxides at a depth of 10 nm (position B in FIG. 4) from the interface of the plating layer specified as described above.
  • the ratio is preferably 0.30 or less with respect to the ratio of metallic aluminum. Since the abundance ratio of aluminum oxides and hydroxides to metallic aluminum is 0.30 or less, even when the pre-coated galvanized steel sheet 20 according to the present embodiment is drawn, more in the molded portion. Good adhesion to the coating film is realized, and it is possible to more reliably suppress the occurrence of floating portions of the coating film.
  • the abundance ratio of the aluminum oxide and hydroxide exceeds 0.30, it may not be possible to develop better coating film adhesion in the molded portion.
  • the abundance ratio of aluminum oxides and hydroxides to such metallic aluminum is more preferably 0.25 or less, still more preferably 0.20 or less. Further, the lower limit of the abundance ratio of aluminum oxides and hydroxides to metallic aluminum is substantially 0.01.
  • the measurement by XPS is carried out for a region having a size of 300 ⁇ m ⁇ 300 ⁇ m, and the abundance ratio calculated as described above is an average value in the measurement region as described above. Means.
  • the pre-coated galvanized steel sheet 20 according to the present embodiment has been described in detail with reference to FIGS. 3A to 4.
  • the molded product 30 according to the present embodiment is subjected to various processing such as deep drawing processing and square cylinder pressing processing on the precoated plated steel sheet 20 as described above. By applying it, it is molded so as to have a desired shape.
  • the mass is 0.5 to 60.0. It contains% aluminum and 0.5-15.0% by mass of magnesium.
  • the plating layer of the molded product 30 according to the present embodiment preferably contains 5% by mass or more and 15% by mass or less of aluminum and 2% by mass or more and 4% by mass or less of magnesium.
  • the plating layer of the molded product 30 contains aluminum and magnesium in the above-mentioned contents, it is possible to more reliably realize the desired corrosion resistance.
  • the rest of the plating layer of the molded product 30 other than aluminum and magnesium is elements, zinc and impurities derived from the external environment.
  • Specific shapes of the molded product 30 according to the present embodiment include various shapes of various parts, including articles mainly used outdoors such as an air conditioner outdoor unit and a water heater. ..
  • processing method used to process the pre-coated galvanized steel sheet 20 according to the present embodiment into a molded product can be adopted as the processing method used to process the pre-coated galvanized steel sheet 20 according to the present embodiment into a molded product. Further, the processing conditions may be appropriately set according to the processing method to be used, the shape of the molded product, and the like.
  • the processing on the top plate of the air conditioner outdoor unit which is an example of the above-mentioned molded product, is a severe molding process for the pre-coated galvanized steel sheet 20.
  • the degree of processing varies depending on the air conditioner company, but in each case, a type of high-speed square tube press is applied to form the top plate of the outdoor unit. At the four corners of the top plate, there will be a compressed part and an extended part.
  • the coating film floats frequently in the compression-processed portion, and the coating film peels off frequently in the stretch-processed portion.
  • the pre-coated plated steel sheet 20 according to the present embodiment is used as a material, the states of metals, oxides and hydroxides of magnesium and aluminum are appropriately controlled at the plating layer interface of the pre-coated plated steel sheet 20. Therefore, it is possible to more reliably suppress the occurrence of the floating portion of the coating film and the peeling of the coating film.
  • the thickness of the pre-coated plated steel sheet of the molded product is compared with the thickness d before molding (which can also be regarded as a non-molded portion).
  • the thickness d before molding which can also be regarded as a non-molded portion.
  • the part is the part where the plated steel sheet is compressed and stretched by processing, and the compression exceeds the stretching.
  • the portion where the thickness is increased by 5% or more is referred to as a “compressed portion”.
  • Such a compressed portion is a portion where the coating film easily floats in the molded product.
  • the chemical conversion treatment film and the coating film are formed.
  • the peeling strength from the primer coating film is 1.00 kN / m or more on average as measured by the SAICAS method.
  • the compressed portion is cut by the SAICAS method, 20% or less of the cutting area is in the form of interfacial peeling, and the remaining cutting area is inside the coating film (when the coating film is composed of a plurality of layers). Is a form of coagulation failure (inside the primer coating film).
  • the chemical conversion treatment film is destroyed by the processing accompanied by compression, and the adhesion is lowered.
  • the internal stress of the coating film is the interface between the chemical conversion treatment film and the coating film (or the primer coating film when the coating film is composed of multiple layers), or the interface between the chemical conversion treatment film and the plating layer.
  • the measurement result by the SAICAS method does not show a significant difference due to the difference in%.
  • the peel strength by the SAICAS method is preferably 1.10 kN / m or more on average, and more preferably 1.20 kN / m or more.
  • the upper limit of the peel strength is substantially 1.5 kN / m.
  • the ratio of the portion in the interface peeling state is preferably 15% or less, more preferably 10% or less. ..
  • the lower the lower limit of the ratio of the portion in the interface peeling state the smaller the better.
  • the lower limit of the ratio of the portion in the interface peeling form is substantially 0%.
  • the peel strength and peeling form of the molded product of interest using the pre-coated galvanized steel sheet by the SAICAS method are measured as follows. First, for the molded product of interest, three or more flat portions considered to be non-molded portions are specified, and the total thickness (including the plated steel plate of the substrate and the coating film on the front and back surfaces) of each flat portion is microgauge. Measure 3 times with and calculate the average value. Such measurements are performed at a plurality of specified locations, and the average value between the locations is further calculated. The average value among the plurality of locations thus obtained is taken as the thickness of the pre-coated plated steel sheet before molding (for example, the thickness d in FIG. 5) in the molded product of interest.
  • a measurement sample (generally 20 mm x 20 mm or more) is cut out from the part that seems to have been subjected to various molding processes such as deep drawing, and smoothed with a steel plate straightener (leveler).
  • the total thickness (including the plated steel plate of the substrate and the coating film on the front and back surfaces) was measured with a microgauge, and the obtained measured value and the obtained as described above were obtained.
  • the rate of increase is calculated based on the thickness of the pre-coated galvanized steel sheet before molding. Of the increase ratios obtained in this way, a portion showing a value of 5% or more is used as a compressed portion of the molded product.
  • the upper limit of the increase ratio as described above is about 11%.
  • the peel strength and the peeling form of the coating film are measured by cutting using a measuring device capable of using the SAICAS method (for example, DN-GS type manufactured by Daipra Wintes). do.
  • the cutting direction in the SAICAS method is parallel to the end line of the steel sheet after drawing.
  • the value of the increase ratio calculated by the above method is within the above range, and the pre-coated plated steel sheets before and after molding are prepared and coated with a coating film release agent from the front and back surfaces of the pre-coated plated steel sheets before and after molding. It has been confirmed that there is no difference in comparison with the value calculated from the thickness of the substrate measured with the film detached.
  • the cutting conditions by the SAICAS method are as follows.
  • a diamond blade (0.3 mm width) is used as a cutting sword, and the horizontal speed is 1 ⁇ m / sec. , Vertical speed 0.1 ⁇ m / sec.
  • After performing diagonal cutting in the constant speed mode of switch to horizontal movement only near the interface and cut with a length of 200 ⁇ m, and measure the average peel strength during horizontal movement.
  • the depth position for switching to horizontal movement was set by specifying the interface position (the position just before cutting the plating) by a preliminary experiment.
  • the peel strength momentarily increases abnormally, so that it can be discriminated.
  • the average peel strength is calculated by excluding it as an abnormal value.
  • the method for measuring the ratio of the interface peeling form and the coagulation fracture form in the cut portion during horizontal movement is as follows.
  • the surface of the cut portion by the SAICAS method is observed with an optical microscope, the difference in the peeling form for each portion can be clearly distinguished.
  • A When an extremely thin coating film remains in the cut portion, coloring by the resin and the pigment in the coating film is observed, so that it can be determined that the peeling form is thin layer cohesive failure in the coating film.
  • B When the cut portion is exfoliated, the appearance of the plated surface of the substrate is observed. Even if such a portion is irradiated with light, no strong reflection is observed, resulting in a blackish appearance.
  • An optical micrograph of a horizontal cutting range (size 300 ⁇ m ⁇ 200 ⁇ m) by the SAICAS method is taken, and the site of cohesive failure of the coating film, interfacial peeling, and coagulation failure of the plating layer within the same range is specified by the above criteria. Then, those areas are measured using image processing software or transparent graph paper. Then, the ratio of the interface peeling area to the area excluding the cohesive fracture of the plating layer from the horizontal cutting range of the SAICAS method is calculated.
  • the pre-coated plated steel sheet for pre-coated steel sheet according to the present embodiment by using the plated steel sheet for pre-coated steel sheet according to the present embodiment, the pre-coated plated steel sheet in which the coating film floating portion and the coating film peeling do not occur in the processed portion such as draw forming. And a molded body made of a pre-coated steel sheet can be obtained.
  • Second Embodiment (About plated steel sheets for pre-coated steel sheets) First, the plated steel sheet for precoated steel sheet according to the second embodiment of the present invention will be described in detail with reference to FIGS. 1A to 2.
  • the plated steel sheet 10 for a precoated steel sheet according to the present embodiment has a steel sheet 101 as a base material and a plating layer 103 located on one side of the steel sheet. Further, in the plated steel sheet 10 for a precoated steel sheet according to the present embodiment, as shown schematically in FIG. 1B, the plated layers 103 may be located on both sides of the steel sheet 101 as a base material.
  • the steel sheet 101 used as the base material of the precoated steel sheet plated steel sheet 10 according to the present embodiment has the same configuration as the steel sheet 101 in the precoated steel sheet plated steel sheet 10 according to the first embodiment, and has the same effect. It is a thing. Therefore, detailed description thereof will be omitted below.
  • the plating layer 20 according to the present embodiment is a layer formed on at least one surface of the steel sheet 101, and improves the corrosion resistance of the plated steel sheet 10 for precoated steel sheets. It is provided to make it.
  • the chemical composition of the plating layer 103 according to the present embodiment has the same structure as that of the plating layer 103 in the plated steel sheet 10 for precoated steel sheets according to the first embodiment, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the average film thickness of the plating layer 103 is the same as that of the first embodiment, and thus will be described in detail below. Is omitted.
  • the plating layer 103 defines the states of zinc metals, oxides, and hydroxides on the surface of the plating layer 103.
  • XPS State analysis of zinc metals, oxides and hydroxides is specified by XPS.
  • Quantum2000 type manufactured by ULVAC-PHI is used, X-ray source: Al K ⁇ , X-ray output 15 kV, 25 W, measurement area: 300 ⁇ 300 ⁇ m square, vacuum degree: 1.5 ⁇ 10-9 Torr, detection accuracy. : 45 o .
  • the sputtering for depth profile analysis is ion species: Ar + , acceleration voltage: 1 kV, region: 1 ⁇ 1 mm, and sputtering rate: 2.7 nm / min (SiO 2 conversion). Sputtering is performed based on the above sputtering rate, and the position specified by such sputtering is regarded as the above "position A".
  • the attribution separation of the ratio (presence ratio) of zinc oxide and hydroxide to metallic zinc is determined from the narrow spectrum in the region of 480 to 515 cm -1 by Zn 2p, for each substance (oxide, water). Calculated from the intensity ratio of peaks attributed to oxides and metals).
  • the ratio of zinc oxide and hydroxide at a depth of 10 nm from the surface of the plating layer (position A in FIG. 2) specified as described above is a metal. It is 7.0 or more with respect to the ratio of zinc.
  • the abundance ratio of zinc oxide and hydroxide to metallic zinc is 7.0 or more, the precoated plated steel sheet using the plated steel sheet 10 for precoated steel sheet having the plating layer 103 according to the present embodiment is squeezed. Even when processed, good coating adhesion in the molded portion is realized, and it is possible to suppress the occurrence of the coating floating portion.
  • the abundance ratio of the zinc oxide and the hydroxide is less than 7.0, good coating film adhesion cannot be exhibited in the molded portion, and a coating film floating portion is generated. Cannot be suppressed.
  • the abundance ratio of zinc oxide and hydroxide with respect to such metallic zinc is preferably 8.0 or more, and more preferably 9.0 or more. Further, the upper limit of the abundance ratio of zinc oxide and hydroxide with respect to metallic zinc is substantially about 20.0.
  • the measurement by XPS is carried out for a region having a size of 300 ⁇ m ⁇ 300 ⁇ m, and the abundance ratio calculated as described above is an average value in the measurement region as described above. Means.
  • the plated steel sheet 10 for precoated steel sheet according to the present embodiment has been described in detail with reference to FIGS. 1A to 2.
  • the plated steel sheet 10 for a precoated steel sheet according to the present embodiment as described above can be manufactured, for example, as follows. First, the surface of the prepared steel sheet 101 is subjected to pretreatment such as cleaning and degreasing as necessary. After that, a plating layer is formed by applying a usual non-oxidizing furnace type hot-dip plating method to the steel sheet 101 which has been pretreated as necessary.
  • a post-treatment step of at least one of acid treatment, alkali treatment, and mechanical cutting treatment is carried out on the steel sheet on which the plating layer is formed. This modifies the surface of the plating layer or removes the surface of the plating layer to satisfy the conditions relating to the XPS spectrum previously mentioned.
  • a hot-dip galvanizing bath having a desired chemical component that is, Al: 0.5 to 60.0% by mass, Mg: 0.5 to 15.0% by mass
  • the balance is Zn and
  • a hot-dip galvanizing bath made of impurities is prepared, and the bath temperature of the plating bath is controlled to about 450 ° C.
  • the obtained steel sheet 101 is immersed in a plating bath, and hot-dip galvanizing is adhered to the surface of the steel sheet so as to have a desired average film thickness.
  • the cooling rate after plating is controlled to 10 ° C./sec or more. This makes it possible to form a plating layer.
  • the plating layer obtained as described above various methods such as acid treatment, alkali treatment, and mechanical cutting treatment are performed while measuring the XPS spectrum with the XPS analyzer set under the measurement conditions as described above.
  • the surface of the plating layer is modified or removed until the conditions relating to the XPS spectrum mentioned above are satisfied.
  • the plated steel plate 10 for precoated steel plate according to the present embodiment having the plating layer 103 as described above can be manufactured.
  • any of the alkaline treatment, the acid treatment, and the mechanical cutting treatment to be applied may be used, and various combinations of these treatments may be used.
  • the higher the alkali concentration and the longer the treatment time the higher the abundance ratio of zinc oxides and hydroxides on the surface of the plating layer tends to be.
  • the spraying time is about 10 seconds or less, the zinc on the surface of the plating layer is oxidized.
  • the abundance ratio of the substance and the hydroxide cannot satisfy the specified condition, but if the spraying time is lengthened, the condition is satisfied, and if the spraying time is lengthened to about 2 minutes, the condition is surely satisfied.
  • this degreasing solution is doubled, the condition is surely satisfied in about 30 seconds.
  • the metallic zinc component is dissolved by the alkali treatment, changed to an oxide or a hydroxide, and re-deposited on the plating surface.
  • the specified conditions can be obtained by treating under weak conditions such as removing the dirt component adhering to the plating surface.
  • the spraying time is set to about 5 to 10 seconds, and the abundance ratio of zinc oxide and hydroxide on the surface of the plating layer is a specified condition. Can be met. However, if sprayed for a longer period of time, the conditions will not be met.
  • a mechanical cutting treatment when a mechanical cutting treatment is performed, such treatment has an effect of removing all of metallic zinc, oxides and hydroxides on the surface of the plating layer. Therefore, it is preferable to use a nylon brush, a grindstone having an appropriate particle size, or the like to perform the treatment under a weak condition that removes the dirt component adhering to the plating surface. After the mechanical cutting process, wash with water to remove cutting stains.
  • the conditions of each treatment also change depending on the initial oxidation state of the plating layer of the steel sheet to be used. Therefore, the plated steel sheet 10 for a precoated steel sheet according to the present embodiment may be manufactured by appropriately selecting the optimum conditions.
  • the precoated plated steel sheet 20 uses the plated steel sheet 10 for precoated steel sheet as described above as the base material.
  • the pre-coated plated steel sheet 20 includes a steel sheet 101, a plating layer 201 located on one side of the steel sheet 101, a chemical conversion coating film 203 located on the plating layer 201, and a coating film 205 located on the chemical conversion coating film 203. have.
  • the plating layer 201, the chemical conversion coating film 203, and the coating film 205 may be formed on both surfaces of the steel sheet 101.
  • the steel plate 101 in the pre-coated plated steel sheet 20 according to the present embodiment has the same configuration as the steel plate 101 in the pre-coated steel plate for pre-coated steel sheet 10 described above, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the plating layer 201 of the precoated plated steel sheet 20 with the formation of the chemical conversion treatment film 203 described later, in the vicinity of the interface between the plating layer 201 and the chemical conversion treatment film 203, atoms and the like contained in each layer may be present. Mutual diffusion and the like may occur.
  • the average chemical composition of the plating layer 201 is the same as that of the plating layer 103 in the plated steel sheet 10 for precoated steel sheets described above, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the chemical conversion treatment film 203 is a film layer located on the plating layer 201, and is known for degreasing steps and cleaning of impurities such as oil and surface oxides adhering to the surface of the plated steel sheet 10 for precoated steel sheets. A layer formed by chemical conversion treatment after being removed in the process.
  • the detailed configuration of the chemical conversion treatment film 203 according to the present embodiment is the same as that of the first embodiment, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the coating film 205 according to the present embodiment is a layer formed on the chemical conversion treatment film 203 as described above.
  • the coating film 205 may be composed of a single layer as schematically shown in FIGS. 3A and 3B, or may be composed of a plurality of two or more layers.
  • the detailed configuration of the coating film 205 according to the present embodiment is the same as that of the first embodiment, and the same effect is obtained. Therefore, detailed description thereof will be omitted below.
  • the zinc metal, oxide and hydroxylation at the interface of the plating layer 201 (more specifically, the interface between the plating layer 201 and the chemical conversion coating film 203). Defines the condition of an object.
  • the “position B” located at a depth of 10 nm from the interface between the plating layer 201 and the chemical conversion coating film 203 toward the inside of the plating layer 201.
  • the state of the metal, oxide, and hydroxide of zinc is specified, and the state of these substances at the interface of the plating layer 201 is used.
  • the position of the interface between the plating layer 201 and the chemical conversion coating film 203 can be specified from the element profile in the depth direction of the precoated plated steel sheet obtained by analyzing the precoated plated steel sheet by XPS. That is, in the present embodiment, the element contained in the chemical conversion treatment film 203 is used as a marker, and the place where the strength of the marker element is halved in the depth direction is defined as the interface between the plating layer 201 and the chemical conversion treatment film 203. ..
  • the measurement conditions for XPS for depth profile analysis and the measurement conditions for state analysis of zinc metals, oxides, and hydroxides are the measurement of XPS in the plated steel sheet 10 for precoated steel sheet shown above. The conditions are the same.
  • the state analysis of zinc metals, oxides and hydroxides is specified by XPS.
  • Quantum2000 type manufactured by ULVAC-PHI is used, X-ray source: Al K ⁇ , X-ray output 15 kV, 25 W, measurement area: 300 ⁇ 300 ⁇ m square, vacuum degree: 1.5 ⁇ 10-9 Torr, detection accuracy. : 45 o .
  • the sputtering for depth profile analysis is ion species: Ar + , acceleration voltage: 1 kV, region: 1 ⁇ 1 mm, and sputtering rate: 2.7 nm / min (SiO 2 conversion). Sputtering is performed based on the above sputtering rate, and the position specified by such sputtering is regarded as the above "position B".
  • the attribution separation of the ratio (presence ratio) of zinc oxide and hydroxide to metallic zinc is determined from the narrow spectrum in the region of 480 to 515 cm -1 by Zn 2p, for each substance (oxide, water). Calculated from the intensity ratio of peaks attributed to oxides and metals).
  • the ratio of zinc oxide and hydroxide at a depth of 10 nm (position B in FIG. 4) from the interface of the plating layer specified as described above is , It is 7.0 or more with respect to the ratio of metallic zinc. Since the abundance ratio of zinc oxide and hydroxide to metallic zinc is 7.0 or more, even when the precoated steel sheet 20 according to the present embodiment is drawn, it is good in the molded portion. Excellent adhesion to the coating film is realized, and it is possible to suppress the occurrence of floating portions of the coating film.
  • the abundance ratio of the zinc oxide and the hydroxide is less than 7.0, good coating film adhesion cannot be exhibited in the molded portion, and a coating film floating portion is generated. Cannot be suppressed.
  • the abundance ratio of zinc oxide and hydroxide with respect to such metallic zinc is preferably 8.0 or more, and more preferably 9.0 or more. Further, the upper limit of the abundance ratio of zinc oxide and hydroxide with respect to metallic zinc is substantially about 20.0.
  • the measurement by XPS is carried out for a region having a size of 300 ⁇ m ⁇ 300 ⁇ m, and the abundance ratio calculated as described above is an average value in the measurement region as described above. Means.
  • the pre-coated galvanized steel sheet 20 according to the present embodiment has been described in detail with reference to FIGS. 3A to 4.
  • the molded product 30 according to the present embodiment is subjected to various processing such as deep drawing processing and square cylinder pressing processing on the precoated plated steel sheet 20 as described above. By applying it, it is molded so as to have a desired shape.
  • the mass is 0.5 to 60.0. It contains% aluminum and 0.5-15.0% by mass of magnesium.
  • the plating layer of the molded product 30 according to the present embodiment preferably contains 5% by mass or more and 15% by mass or less of aluminum and 2% by mass or more and 4% by mass or less of magnesium.
  • the plating layer of the molded product 30 contains aluminum and magnesium in the above-mentioned contents, it is possible to more reliably realize the desired corrosion resistance.
  • the rest of the plating layer of the molded product 30 other than aluminum and magnesium is elements, zinc and impurities derived from the external environment.
  • Specific shapes of the molded product 30 according to the present embodiment include various shapes of various parts, including articles mainly used outdoors such as an air conditioner outdoor unit and a water heater. ..
  • processing method used to process the pre-coated galvanized steel sheet 20 according to the present embodiment into a molded product can be adopted as the processing method used to process the pre-coated galvanized steel sheet 20 according to the present embodiment into a molded product. Further, the processing conditions may be appropriately set according to the processing method to be used, the shape of the molded product, and the like.
  • the processing on the top plate of the air conditioner outdoor unit which is an example of the above-mentioned molded product, is a severe molding process for the pre-coated galvanized steel sheet 20.
  • the degree of processing varies depending on the air conditioner company, but in each case, a type of high-speed square tube press is applied to form the top plate of the outdoor unit. At the four corners of the top plate, there will be a compressed part and an extended part.
  • the coating film floats frequently in the compression-processed portion, and the coating film peels off frequently in the stretch-processed portion.
  • the precoated plated steel sheet 20 according to the present embodiment is used as a material, the states of zinc metal, oxide and hydroxide are appropriately controlled at the plating layer interface of the precoated plated steel sheet 20. In addition, it is possible to more reliably suppress the occurrence of the floating portion of the coating film and the peeling of the coating film.
  • the pre-coated plated steel sheet for pre-coated steel sheet according to the present embodiment by using the plated steel sheet for pre-coated steel sheet according to the present embodiment, the pre-coated plated steel sheet in which the coating film floating portion and the coating film peeling do not occur in the processed portion such as draw forming. And a molded body made of a pre-coated steel sheet can be obtained.
  • the third embodiment of the present invention shown below focuses on both the state of zinc oxide and hydroxide on the surface of the plated steel sheet and the state of aluminum and magnesium oxide and hydroxide on the surface of the plated steel sheet. It is an embodiment.
  • the plated steel sheet 10 for a precoated steel sheet according to the present embodiment has a steel sheet 101 as a base material and a plating layer 103 located on one side of the steel sheet. Further, in the plated steel sheet 10 for a precoated steel sheet according to the present embodiment, as shown schematically in FIG. 1B, the plated layers 103 may be located on both sides of the steel sheet 101 as a base material.
  • the steel plate 101 used as the base material of the plated steel plate 10 for precoated steel plate according to the present embodiment has the same configuration as the steel plate 101 in the plated steel plate 10 for precoated steel plate according to the first embodiment and the second embodiment. It has the same effect. Therefore, detailed description thereof will be omitted below.
  • the plating layer 103 As well, except that attention is paid to both the state of the oxide and the hydroxide of zinc and the state of the oxide and the hydroxide of aluminum and magnesium on the surface of the plated steel sheet, the first embodiment and It has the same structure as the plating layer 103 in the plated steel sheet 10 for precoated steel sheet according to the second embodiment, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the method for analyzing the states of aluminum and magnesium metals, oxides and hydroxides the method for analyzing the states of zinc metals, oxides and hydroxides, and the conditions to be satisfied by the obtained analysis results, It is as described in 1 Embodiment and 2nd Embodiment.
  • the ratio of magnesium oxide and hydroxide is 2.0 with respect to the ratio of metallic magnesium.
  • the ratio of the oxide and the hydroxide of zinc is 7.0 or more with respect to the ratio of metallic zinc.
  • the coating is better in the formed portion. Film adhesion is realized, and it is possible to more reliably suppress the occurrence of floating portions of the coating film.
  • the states of the oxides and hydroxides of magnesium and zinc are as described above, and the ratio of the oxides and hydroxides of aluminum is 1.3 or more with respect to the ratio of metallic aluminum. Is more preferable. In such a state, even when the pre-coated plated steel sheet using the plated steel sheet 10 having the plating layer 103 according to the present embodiment is drawn, even better coating film adhesion in the molded portion is achieved. Is realized, and it becomes possible to more reliably suppress the occurrence of the floating portion of the coating film.
  • the plated steel sheet 10 for precoated steel sheet according to the present embodiment has been described in detail with reference to FIGS. 1A to 2.
  • the plated steel sheet 10 for a pre-coated steel sheet can be manufactured by the manufacturing methods as described in the first embodiment and the second embodiment.
  • the plating surface is desorbed to form a fresh new surface, and by performing alkaline treatment in this state, zinc and magnesium oxides or oxides of magnesium or magnesium or This is thought to be due to the realization of re-deposition of hydroxide on the plated surface.
  • the abundance ratio of aluminum oxides or hydroxides is relative. It is possible to raise it to. This is because the convex surface of the plating has a high content of aluminum, so that the alkali treatment of the new surface of such a portion increases the elution of aluminum, and as a result, the abundance ratio of aluminum oxide or hydroxide increases. it is conceivable that.
  • the precoated plated steel sheet 20 uses the plated steel sheet 10 for precoated steel sheet as described above as the base material.
  • the pre-coated plated steel sheet 20 includes a steel sheet 101, a plating layer 201 located on one side of the steel sheet 101, a chemical conversion coating film 203 located on the plating layer 201, and a coating film 205 located on the chemical conversion coating film 203. have.
  • the plating layer 201, the chemical conversion coating film 203, and the coating film 205 may be formed on both surfaces of the steel sheet 101.
  • the steel plate 101 in the pre-coated plated steel sheet 20 according to the present embodiment has the same configuration as the steel plate 101 in the pre-coated steel plate for pre-coated steel sheet 10 described above, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the plating layer 201 of the precoated plated steel sheet 20 with the formation of the chemical conversion treatment film 203 described later, in the vicinity of the interface between the plating layer 201 and the chemical conversion treatment film 203, atoms and the like contained in each layer may be present. Mutual diffusion and the like may occur.
  • the average chemical composition of the plating layer 201 is the same as that of the plating layer 103 in the plated steel sheet 10 for precoated steel sheets described above, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the states of magnesium, aluminum, zinc metals, oxides and hydroxides shown by the plating layer 201 of the precoated plated steel sheet 20 according to the present embodiment and the measuring method thereof are described in the first embodiment and the second embodiment. It is as shown in the form.
  • the chemical conversion treatment film 203 and the coating film 205 are located above the plating layer 201.
  • the detailed configuration of the chemical conversion treatment film 203 according to the present embodiment is the same as that of the first embodiment and the second embodiment, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the detailed configuration of the coating film 205 according to the present embodiment is the same as that of the first embodiment and the second embodiment, and has the same effect. Therefore, detailed description thereof will be omitted below.
  • the precoated galvanized steel sheet 20 according to the present embodiment has been described above with reference to FIGS. 3A to 4.
  • the molded product 30 according to the present embodiment is subjected to various processing such as deep drawing processing and square cylinder pressing processing on the precoated plated steel sheet 20 as described above. By applying it, it is molded so as to have a desired shape.
  • various processing such as deep drawing processing and square cylinder pressing processing on the precoated plated steel sheet 20 as described above.
  • it is molded so as to have a desired shape.
  • the details of the molded product 30 are as described in the first embodiment and the second embodiment, detailed description thereof will be omitted below.
  • the pre-coated plated steel sheet and the pre-coated plated steel sheet in which the coating film floating portion and the coating film peeling do not occur in the processed portion such as draw forming are used.
  • a molded body made of a pre-coated steel sheet can be obtained.
  • the plated steel sheet for pre-coated steel sheet, the pre-coated hard and soft, and the molded product according to the present invention will be specifically described with reference to Examples and Comparative Examples.
  • the examples shown below are merely examples of the plated steel sheet for precoated steel sheet, the precoated plated steel sheet and the molded product according to the present invention, and the plated steel sheet for precoated steel sheet, the precoated plated steel sheet and the molded product according to the present invention are as follows. It is not limited to an example.
  • the first test example shown below is a test example relating to a plated steel sheet for precoated steel sheets, a precoated plated steel sheet, and a molded product according to the first embodiment.
  • A1 Zn-11% Al-3% Mg-0.2% Si hot-dip galvanized steel sheet (plate thickness 0.60 mm, plating adhesion amount 40 g / m 2 )
  • A2 Zn-6% Al-3% Mg hot-dip galvanized steel sheet (plate thickness 0.60 mm, plating adhesion amount 40 g / m 2 )
  • A3 Zn-55% Al-2% Mg-1.6% Si hot-dip galvanized steel sheet (plate thickness 0.35 mm, plating adhesion 75 g / m 2 )
  • A4 Hot-dip galvanized steel sheet (plate thickness 0.60 mm, plating adhesion amount 40 g / m 2 )
  • A5 Zn-55% Al-1.6% Si hot-dip galvanized steel sheet (plate thickness 0.35 mm, plating adhesion amount 75 g / m 2 )
  • S1 Water-based coating composition consisting of tannic acid, silane coupling agent, silica fine particles, and polyester resin
  • S2 Water-based coating composition consisting of silane coupling agent, phosphate, and acrylic resin
  • S3 Silane coupling agent, foot A water-based coating composition consisting of titanic acid, silconic fluoride acid, and urethane resin.
  • the coating compositions of S1 to S3 were bar-coated on the plated steel sheet for pre-coated steel sheet so as to have a predetermined adhesion amount at the time of drying, then dried in a hot air furnace at a metal surface reaching temperature of 70 ° C. and air-dried.
  • a two-layer type coating film consisting mainly of a primer coating film and a top coating film was mainly prepared, and a single-layer type coating film consisting only of a top coating film without a primer coating film was also formed. ..
  • P1 Polyester / melamine resin curing composition (FLC641 manufactured by Nippon Paint Industrial Coatings Co., Ltd.)
  • P2 Polyester / isocyanate resin curing composition (FLC690 manufactured by Nippon Paint Co., Ltd.)
  • P3 Epoxy / melamine resin curing composition
  • the P1 to P3 are bar-coated on a galvanized steel sheet for precoated steel sheet that has undergone the above chemical conversion treatment so as to have a predetermined drying thickness (1 to 12 ⁇ m), and then the metal surface reaching temperature of 215 ° C. is reached in a hot air furnace. It was dried in.
  • T1 High molecular weight polyester / melamine resin curing composition (FLC7000 manufactured by Nippon Paint Co., Ltd.)
  • T2 Polyester / melamine resin curing composition (FLC100HQ manufactured by Nippon Paint Co., Ltd.)
  • the metal surface reaching temperature is 230 ° C. in a hot air furnace. It was dried in.
  • the XPS measurement conditions and the sputtering rate in the depth profile measurement were set as shown above.
  • the interface position between the chemical conversion coating and the plating layer paying attention to the depth profile of silicon in the depth direction of the precoated plated steel sheet by X-ray photoelectron spectroscopy, the strength of silicon is halved in the depth direction. The position was specified and used as the interface between the chemical conversion coating and the plating layer.
  • the cylindrical cup drawing was carried out as follows.
  • the pre-coated plated steel sheet obtained as described above is drawn into a cylindrical cup with a drawing ratio of 2.0 so that the measurement target surface is on the outside, and the vicinity of the steel plate end of the cylindrical body is cut with a snips or the like.
  • a sufficient size generally 20 ⁇ 20 mm or more
  • the steel sheet was smoothed by a steel sheet straightener (leveler).
  • the portion of the obtained steel sheet piece whose thickness is increased by 5% or more as compared with that before molding is specified by the method described above, and the peel strength and peeling form of the coating film of the specified portion are determined by the SAICAS method. It was cut and measured with.
  • the cutting direction was set to be parallel to the end line of the steel sheet after drawing.
  • the ratio of oxides and hydroxides to the metal content of magnesium and aluminum at the surface of the plated plate before molding and the interface of the plated steel plate after painting, and the peeling strength and peeling by SAICAS of the compressed portion of the molded product Since the morphology meets the standard, no coating film floating or coating film peeling was observed even in the actual processing of the top plate of the air conditioner outdoor unit.
  • the second test example shown below is a test example relating to a plated steel sheet for precoated steel sheets, a precoated plated steel sheet, and a molded product according to the second embodiment.
  • a two-layer type coating film consisting mainly of a primer coating film and a top coating film is mainly produced, and a single-layer type coating film consisting of only a top coating film without a primer coating film is also formed. bottom.
  • a primer coating film was formed in the same manner as in the first test example.
  • a top coating film was formed in the same manner as in the first test example.
  • the surface of the plated steel sheet for precoated steel sheet before the chemical conversion treatment and the interface of the plated steel sheet for precoated steel sheet after the coating film were formed were observed by X-ray photoelectron spectroscopy (XPS), and zinc (Zn) was sputter-etched from the surface and interface by 10 nm.
  • the ratio was calculated from the ratio of the peak intensities of the oxide and the hydroxide (the region of 480 to 515 cm -1 by 2p) and the peak intensities of the metal.
  • the XPS measurement conditions and the sputtering rate in the depth profile measurement were set as shown above.
  • the interface position between the chemical conversion coating and the plating layer paying attention to the depth profile of silicon in the depth direction of the precoated plated steel sheet by X-ray photoelectron spectroscopy, the strength of silicon is halved in the depth direction. The position was specified and used as the interface between the chemical conversion coating and the plating layer.
  • Performance evaluation was carried out in the same manner as in the first test example.
  • the evaluation method and evaluation criteria are the same as those in the first test example.
  • the third test example shown below is a test example relating to a plated steel sheet for precoated steel sheets, a precoated plated steel sheet, and a molded product according to the third embodiment.
  • the plated steel sheet for pre-coated steel sheet, the pre-coated plated steel sheet and the molded product were prepared in the same manner as in the first test example and the second test example.
  • the obtained plated steel sheets for pre-coated steel sheets, pre-coated plated steel sheets and molded products were similarly evaluated according to the measurement methods and evaluation methods shown in the first test example and the second test example.

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PCT/JP2021/036808 2020-10-23 2021-10-05 プレコート鋼板用めっき鋼板、プレコートめっき鋼板及び成形品 WO2022085434A1 (ja)

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JP2007002288A (ja) * 2005-06-22 2007-01-11 Nippon Steel Corp 塗装下地用めっき鋼板とその製造方法及び塗装鋼板
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JP2012082511A (ja) * 2010-09-15 2012-04-26 Nisshin Steel Co Ltd 黒色めっき鋼板
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JPH07331403A (ja) * 1994-06-07 1995-12-19 Nippon Steel Corp 高強度合金化溶融亜鉛メッキ鋼板の製造方法
JP2007002288A (ja) * 2005-06-22 2007-01-11 Nippon Steel Corp 塗装下地用めっき鋼板とその製造方法及び塗装鋼板
JP2007056307A (ja) * 2005-08-24 2007-03-08 Nippon Steel Corp 塗装後耐食性に優れた亜鉛系めっきが施された熱間プレス鋼材
JP2012082511A (ja) * 2010-09-15 2012-04-26 Nisshin Steel Co Ltd 黒色めっき鋼板
JP2014173137A (ja) * 2013-03-08 2014-09-22 Nippon Steel & Sumitomo Metal 端面耐食性およびスポット溶接性に優れた合金化溶融亜鉛めっき鋼板

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