WO2020121899A1 - HIGH-STRENGTH ZINC-PLATED STEEL SHEET HAVING TENSILE STRENGTH OF 1180 MPa OR MORE AND METHOD FOR MANUFACTURING SAME, AND SURFACE TREATMENT SOLUTION - Google Patents
HIGH-STRENGTH ZINC-PLATED STEEL SHEET HAVING TENSILE STRENGTH OF 1180 MPa OR MORE AND METHOD FOR MANUFACTURING SAME, AND SURFACE TREATMENT SOLUTION Download PDFInfo
- Publication number
- WO2020121899A1 WO2020121899A1 PCT/JP2019/047285 JP2019047285W WO2020121899A1 WO 2020121899 A1 WO2020121899 A1 WO 2020121899A1 JP 2019047285 W JP2019047285 W JP 2019047285W WO 2020121899 A1 WO2020121899 A1 WO 2020121899A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- steel sheet
- film
- metal salt
- strength
- galvanized steel
- Prior art date
Links
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Images
Classifications
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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
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- C23C2/26—After-treatment
- C23C2/28—Thermal after-treatment, e.g. treatment in oil bath
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
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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
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
Definitions
- the present invention relates to a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, a method for manufacturing the same, and a surface treatment liquid.
- TECHNICAL FIELD The present invention relates to a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which is a steel sheet suitable mainly for strength members for automobiles and building materials, and has excellent delayed fracture resistance, and a manufacturing technique thereof.
- Delayed fracture is a state in which high-strength steel is subjected to static load stress (load stress of tensile strength or less), and when a certain time has elapsed, it appears to be suddenly brittle with almost no plastic deformation. This is a phenomenon in which various destructions occur. Delayed fracture is more likely to occur as the strength of the steel material becomes higher, and becomes more prominent particularly in high-strength steel having a tensile strength of 1180 MPa or more.
- Patent Document 1 In order to prevent such delayed fracture in high-strength steel sheets, for example, in Patent Document 1, a study is made to weaken the delayed fracture sensitivity by adjusting the structure and composition of the steel sheet. Further, in Patent Document 2, a study on a high-strength galvannealed steel sheet for preventing delayed fracture is made.
- an object of the present invention is to solve the problems of the prior art as described above and to provide a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which is excellent in delayed fracture resistance.
- Another object of the present invention is to provide a method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which has the above-mentioned excellent properties, and a surface treatment liquid.
- the "high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more" of the present invention is also simply referred to as "high-strength galvanized steel sheet”.
- the present inventors have conducted extensive studies and research on means for reducing the amount of hydrogen that penetrates into the steel sheet in order to prevent delayed fracture of the galvanized steel sheet in the use environment. As a result, by forming a resin film containing a specific metal salt and not containing other specific particle components on the surface of the galvanized steel sheet, hydrogen intrusion into the steel sheet is suppressed, and excellent delayed fracture resistance It was found that
- a galvanized steel sheet having a tensile strength of 1180 MPa or more has a coating containing the coating (x), and the coating (x) is an organic resin (a).
- a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group, and a molybdic acid group, and the maximum particle size other than the metal salt (b) is
- the coating film (x) does not contain a particle component having a thickness equal to or larger than the film thickness, the film thickness is 0.3 ⁇ m or more, and the content of the metal salt (b) in the film (x) is 5% by mass or more, A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more.
- the metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum, and has a tensile strength of 1180 MPa or more.
- the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group, and a silicic acid group.
- the metal salt (b) has a tensile strength of 1180 MPa or more, which is 50 mg/m 2 or more per one side of the steel sheet. High strength galvanized steel sheet.
- the metal salt (b) is aluminum dihydrogen tripolyphosphate, and the film thickness of the film (x) is 1.0 ⁇ m or more.
- the coating (x) does not contain conductive particles and solid lubricant particles, and has high strength zinc having a tensile strength of 1180 MPa or more. Plated steel sheet.
- the coating (x) has high tensile strength of 1180 MPa or more, containing no particle component other than the metal salt (b). Galvanized steel sheet.
- the content of the metal salt (b) present in the coating (x) is 40% by mass or less, and a tensile strength of 1180 MPa or more. High strength galvanized steel sheet with strength.
- a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more which has a coating containing a coating (x) on the surface of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including a galvannealed steel sheet).
- the film (x) comprises an organic resin (a) and a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group and a molybdic acid group.
- the metal salt (b) does not contain a particle component having a maximum particle size of at least the film thickness of the coating (x), and has a film thickness of 0.3 ⁇ m or more.
- the coating film (x) contains the organic resin (a) and the metal salt (b), and other than the metal salt (b) Is formed by adhering to the surface where the coating (x) is to be formed, a surface treatment liquid that does not contain a particle component having a maximum particle size that is greater than or equal to the thickness of the coating (x) to be formed.
- the metal salt (b) is a metal salt containing at least one of an alkali metal, an alkaline earth metal and aluminum, and has high tensile strength of 1180 MPa or more. Manufacturing method of galvanized steel sheet.
- the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group, 1180 MPa or more. Of manufacturing a high-strength galvanized steel sheet having the above tensile strength.
- the high-strength zinc having a tensile strength of 1180 MPa or more, in which the amount of the metal salt (b) deposited on one surface of the steel sheet is 50 mg/m 2 or more, in the manufacturing method according to any one of [10] to [12] above. Manufacturing method of plated steel sheet.
- the metal salt (b) is aluminum dihydrogen tripolyphosphate, and the film (x) has a film thickness of 1.0 ⁇ m or more.
- the coating (x) is a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more that does not contain conductive particles and solid lubricant particles. Production method.
- the surface treatment liquid is a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more that does not contain particle components other than the metal salt (b).
- Production method [17]
- the film (x) has a tensile strength of 1180 MPa or more, in which the content of the metal salt (b) is 40% by mass or less. Method for manufacturing high strength galvanized steel sheet.
- a film including a film (x) for suppressing delayed fracture of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including galvannealed steel sheet) is formed on the surface of the galvanized steel sheet.
- the coating includes an inorganic coating and a coating (x) formed on the inorganic coating, and the inorganic coating is a silane compound.
- the coating includes an inorganic coating and a coating (x) formed on the inorganic coating, and at least one selected from a silane compound and a zirconium compound.
- a surface treatment solution containing a seed (component (c)) onto the galvanized steel sheet, the inorganic coating having an amount of component (c) deposited on one side of the steel sheet of 200 to 500 mg/m 2 is obtained.
- the high-strength galvanized steel sheet of the present invention has excellent delayed fracture resistance.
- the high-strength galvanized steel sheet of the present invention has an excellent delayed fracture resistance in which the specific coating formed on the galvanized surface suppresses the intrusion of hydrogen into the steel sheet through corrosion inhibition and effectively suppresses the delayed fracture. Have sex.
- the high-strength galvanized steel sheet of the present invention which has a more optimized film structure, has excellent delayed fracture resistance and good post-paint corrosion resistance.
- the high-strength galvanized steel sheet of the present invention which has a more optimized coating structure, has excellent delayed fracture resistance and good coating adhesion.
- the high-strength galvanized steel sheet of the present invention is mainly suitable for strength members for automobiles and building materials. Since the high-strength galvanized steel sheet of the present invention can reduce the thickness of the steel sheet by improving the strength of the steel sheet, it is possible to reduce the weight of the strength member applied to the fields of automobiles and construction materials.
- the high-strength galvanized steel sheet according to the first embodiment of the present invention has a coating (x) on the surface of a galvanized steel sheet (including an alloyed hot-dip galvanized steel sheet) having a tensile strength of 1180 MPa or more.
- the film (x) contains a specific metal salt.
- the steel plate (base steel plate) that serves as the base (substrate) of the high-strength galvanized steel plate of the present invention is a high-strength steel plate having a tensile strength of 1180 MPa or more, and more preferably a high-strength steel plate having a tensile strength of 1480 MPa or more. Steel sheets with low tensile strength are essentially less prone to delayed fracture.
- the effect of the present invention is exhibited even in a steel sheet having a low tensile strength, but is remarkably exhibited in a high strength steel sheet having a tensile strength of 1180 MPa or more, and is more remarkably exhibited in a high strength steel sheet having a tensile strength of 1480 MPa or more. is there.
- the chemical composition and steel structure of the base steel sheet are not particularly limited.
- a high-strength steel sheet having a tensile strength of 1180 MPa or more which is often used in an automobile field, a construction material field, and the like, particularly in an automobile field, is preferable, and a high-strength steel sheet having a tensile strength of 1480 MPa or more is more preferable.
- the high-strength steel sheet preferably used as the base steel sheet may have any composition and structure as long as it has a desired tensile strength.
- Such high-strength steel sheet is, for example, a solid solution obtained by adding an interstitial solid solution element such as C and N and a substitutional solid solution element such as Si, Mn, P and Cr in order to improve various properties such as mechanical properties.
- the composition of such a high-strength steel sheet is, for example, C: 0.1 to 0.4 mass%, Si: 0 to 2.5 mass%, Mn: 1 to 3 mass%, P: 0 to 0.05. %, S: 0 to 0.005% by mass, with the balance being Fe and inevitable impurities.
- a composition containing one or more kinds of arbitrary elements such as Cu, Ti, V, Al and Cr in the above composition can be mentioned. Generally, it is preferable that these optional elements are added in a total amount of about 10% by mass.
- Examples of commercially available high-strength steel sheets include JFE-CA1180, JFE-CA1370, JFE-CA1470, JFE-CA1180SF, JFE-CA1180Y1, JFE-CA1180Y2 (above, JFE Steel Corp.). Manufactured by Nippon Steel & Sumitomo Metal Co., Ltd. and the like can be exemplified without limitation.
- the plate thickness of the high-strength steel plate is not particularly limited, but as an example, the plate thickness of the high-strength steel plate is preferably 0.8 mm or more, more preferably 1.2 mm or more. Moreover, as an example, the plate thickness of the high-strength steel plate is preferably 2.5 mm or less, and more preferably 2.0 mm or less.
- the zinc plating that coats the high-strength steel sheet may be formed by any plating method such as hot dipping, electroplating, electroless plating, and vapor deposition plating.
- hot dip galvanization hot dip galvanized steel sheet
- electrogalvanization electrogalvanized steel sheet
- the galvanized steel sheet according to the present invention includes a galvanized steel sheet formed by the above plating method, and includes, for example, a hot-dip galvanized steel sheet, an electrogalvanized steel sheet, an electroless galvanized steel sheet, and a vapor-deposited galvanized steel sheet.
- the galvanized steel sheet of the present invention includes an alloyed hot dip galvanized steel sheet obtained by an alloying treatment after the hot dip galvanizing.
- the high-strength galvanized steel sheet of the present invention has a tensile strength of 1180 MPa or more on the surface of the galvanized steel sheet, organic resin (a), phosphoric acid group, phosphorous acid group, silicic acid group, molybdic acid group
- a film containing a film (x) containing a metal salt (b) containing at least one of them is formed.
- This film (x) may contain two or more kinds of metal salts (b).
- the metal salt (b) is retained on the surface of the steel sheet. This is because it functions as a barrier layer that shields the surface of the steel sheet from the corrosive environment when exposed to the corrosive environment, and also has a function of firmly holding the metal salt (b) on the surface of the steel sheet.
- the type of the organic resin (a) is not particularly limited, and examples thereof include epoxy resin, modified epoxy resin, urethane resin, alkyd resin, acrylic resin, polyethylene resin, polyolefin resin such as polybutadiene resin, polyester resin, amino resin, phenol resin, A fluororesin, a silicone resin, etc. are mentioned, and 1 or more types of these can be used. Further, among these, urethane resin, epoxy resin, acrylic resin, and polyethylene resin are particularly preferable because they have a high effect of blocking moisture and chloride, which are corrosion factors.
- the metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group, and a molybdic acid group forms a chelate complex with Zn 2+ and forms a stable passive film.
- the metal salt (b) include inorganic metal salts.
- the metal salt (b) include metal salts containing alkali metals, alkaline earth metals, aluminum, zinc, zirconium and the like.
- Examples of the metal salt (b) include sodium polyphosphate (sodium diphosphate), sodium tripolyphosphate, aluminum dihydrogen tripolyphosphate, zinc polyphosphate, zinc tripolyphosphate, calcium phosphate, magnesium zinc phosphate, zinc phosphite.
- Calcium phosphite zinc calcium phosphite, zinc magnesium phosphite, calcium zirconium silicate, zirconium phosphate, zinc molybdate, calcium molybdate, aluminum phosphomolybdate, and the like, and use one or more of these. You can
- a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum is particularly preferable because it has an effect of keeping pH high (pH buffering effect).
- Alkali metals, alkaline earth metals, and aluminum have a high ionization tendency, and thus tend to form a hydroxide when ionized, as compared with other metal salts. That is, since the hydroxide ion (OH ⁇ ) is consumed less than other metal ions, it is considered that the pH is kept high (the OH concentration is high). Therefore, the metal salt (b) is preferably a metal salt containing at least one selected from alkali metals, alkaline earth metals and aluminum. Also in this case, the film (x) can contain two or more kinds of metal salts (b).
- the metal salt (b) is preferably a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group from the viewpoint of cost advantage.
- the content of metal salt (b) in the film (x) (ratio to the film mass) is 5% by mass. It is necessary to be above.
- the content of the metal salt (b) is preferably 44% by mass or less, and more preferably 40% by mass or less because the property deteriorates.
- the amount of the metal salt (b) deposited on one side of the steel sheet is small, the effect of suppressing the occurrence of delayed fracture may not be sufficiently obtained. Therefore, the amount of the metal salt (b) deposited on one side of the steel sheet It is preferably 50 mg/m 2 or more.
- the film thickness of the film (x) if the film (x) is too thin, it cannot function as a barrier layer that shields the steel sheet from the corrosive environment, so the film thickness of the film (x) is 0.3 ⁇ m or more. ..
- the film thickness of the film (x) is 0.3 ⁇ m or more. ..
- the metal salt (b) is aluminum dihydrogen tripolyphosphate, and the film thickness of the film (x) is 1.0 ⁇ m or more.
- the film (x) formed on the galvanized steel sheet in the present invention contains the organic resin (a) and the specific metal salt (b) as described above.
- the metal salt (b) may be contained in the film (x) in a dissolved state or in the form of particles.
- the particle size is not particularly limited.
- the film (x) does not contain, other than the metal salt (b), a particle component having a maximum particle diameter equal to or larger than the film thickness of the film (x).
- a particle component having a maximum particle diameter equal to or larger than the film thickness of the film (x) may be added to the coating for the purpose of improving the conductivity of the coating and improving the weldability.
- particle components may be added for various purposes such as addition of a solid lubricant in order to improve press workability.
- the coating (x) does not contain any particle component other than the metal salt (b) whose maximum particle diameter is equal to or larger than the thickness of the coating (x).
- a particle component include conductive particles and solid lubricant particles.
- Examples of the conductive particles include ceramic particles, iron alloy particles, stainless particles and the like.
- Examples of the solid lubricant particles include inorganic solid lubricant particles such as molybdenum disulfide, graphite and boron nitride.
- the film (x) Since the lower limit of the film thickness of the film (x) is 0.3 ⁇ m, if the maximum particle size of the particle component allowed to be contained is less than 0.3 ⁇ m, preferably 0.2 ⁇ m or less, the film (x) The condition is satisfied regardless of the film thickness of.
- the maximum particle diameter of the particle component means that the film (x) is dissolved in an organic solvent capable of dissolving the film (x) such as toluene or acetone, and then the particle component is changed to polytetrafluoroethylene or the like. It is the maximum value of the particle size distribution obtained by collecting with a filter, washing and dispersing in an electrolyte solvent, and then measuring the volume sphere equivalent diameter by the Coulter method.
- the collected particle components are dispersed in an electrolyte solvent and then separated by a centrifugal method to separate each of the particle components.
- the volume sphere equivalent diameter of the particle component may be measured by the Coulter method.
- the catalog value of the maximum particle size of the particle component may be used as the maximum particle size of the particle component.
- the maximum particle size referred to here means the maximum particle size of the primary particles.
- the film (x) of the present invention contains the organic resin (a) and the specific metal salt (b), and does not contain the above-mentioned large particle component other than the metal salt (b).
- the metal salt (b) there are no particles that act as coating film defects in the film, and the vicinity of the particles does not become the starting point of corrosion, and delayed fracture resistance can be secured.
- the film (x) does not contain conductive particles and solid lubricant particles, and the film (x) does not contain particle components other than the metal salt (b). It can be said that the film (x) is more preferably composed of only the organic resin (a) and the metal salt (b).
- the high-strength galvanized steel sheet according to the present invention may have the coating (x) formed on one side of the steel sheet or both sides of the steel sheet.
- fluorescent X-ray analysis As a method for measuring the content of the metal salt (b) in the film (x) and the amount attached on one side of the steel sheet, there is fluorescent X-ray analysis, for example. Specifically, it can be calculated by irradiating the film surface with X-rays, measuring the intensity of fluorescent X-rays of the metal element contained in the metal salt (b), and comparing with the calibration curve.
- the cross section of the film is observed, and the thickness of the film (x) (from the galvanized steel plate surface of the substrate to the film (x) Thickness up to the surface of) is measured, and the average value thereof is taken as the film thickness.
- the cross-section processing method is not particularly limited, and examples thereof include FIB (Focused Ion Beam) processing.
- the organic resin (a), a phosphoric acid group, a phosphorous acid group, on the surface of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including a galvannealed steel sheet) as described above Contains a metal salt (b) containing at least one of a silicic acid group and a molybdic acid group, and has a maximum particle size of at least the film thickness of the film (x) to be formed, other than the metal salt (b).
- the above-mentioned coating (x) is formed on the surface of the galvanized steel sheet by adhering a surface treatment liquid (surface treatment liquid for resin film formation) that does not contain a certain particle component.
- the lower limit of the film thickness of the film (x) to be formed is set in advance and the maximum value corresponding to the film thickness is set. It suffices if the surface treatment liquid contains a particle component having a particle size.
- the maximum particle diameter of the particle component contained in the surface treatment liquid is less than 0.3 ⁇ m, preferably 0.2 ⁇ m or less. For example, the above conditions are satisfied regardless of the film thickness of the film (x).
- the reasons for limiting the film thickness of the formed film (x) and the content of the metal salt (b) are the same as those for the high-strength galvanized steel sheet described above.
- the preferable conditions in this manufacturing method are as follows, and the reason is the same as the reason for the high-strength galvanized steel sheet described above.
- the metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum.
- the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group.
- the amount of the metal salt (b) deposited on one surface of the steel sheet in the film (x) is 50 mg/m 2 or more.
- the metal salt (b) is aluminum dihydrogen tripolyphosphate, the film thickness of the film (x) is 1.0 ⁇ m or more, and the content of aluminum dihydrogen tripolyphosphate in the film (x) is 17 to Must be 45% by mass.
- the surface treatment liquid should not contain conductive particles or solid lubricant particles. Preferably, the surface treatment liquid contains no particle component other than the metal salt (b). Particularly preferably, the surface treatment liquid contains only the organic resin (a) and the metal salt (b) in the solvent.
- the content of the metal salt (b) in the film (x) is 44 mass% or less, preferably 40 mass% or less.
- the film thickness of the film (x) is 4.0 ⁇ m or less.
- the organic resin (a) is dissolved and/or dispersed in a solvent (water and/or organic solvent), and the metal salt (b) (and, if necessary, And other components) are added to the surface of the galvanized steel sheet to coat the surface of the galvanized steel sheet, followed by drying (generally heat drying).
- a solvent water and/or organic solvent
- the metal salt (b) and, if necessary, And other components
- any coating means such as a bar coater, a roll coater (3 roll system, 2 roll system, etc.), a squeeze coater, a die coater, etc. may be used. It is also possible to adjust the coating amount, make the appearance uniform, and make the film thickness uniform by an air knife method or a roll squeezing method after the coating treatment using a squeeze coater, the dipping treatment, and the spray treatment.
- the method of heating and drying the surface treatment liquid that is attached to the surface of the galvanized steel sheet and coated is arbitrary, and for example, a dryer, a hot-air stove, a high-frequency induction heating furnace, an infrared furnace, or the like can be used.
- the content of the metal salt (b) in the coating (x) is the mixing ratio of the organic resin (a) and the metal salt (b). It can be adjusted by changing. Further, the amount of the metal salt (b) attached and the film thickness of the film (x) per one side of the steel sheet can be adjusted by changing the concentration of the surface treatment liquid and the amount of the attached (coating amount).
- the method for producing the high-strength steel sheet used as the plating base steel sheet in the present invention is not particularly limited. In order to facilitate understanding of the present invention, a series of processes from steelmaking will be briefly described with an example. However, the manufacturing process of the high-strength steel plate to be the plated base steel plate is not limited to the following examples.
- the surface treatment liquid of the present invention comprises a galvanized steel sheet having a coating (x) for suppressing delayed fracture of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including galvannealed steel sheet).
- the lower limit of the film thickness of the film (x) to be formed by applying the surface treatment liquid is set in advance, and the film thickness It suffices to include a particle component having a maximum particle diameter corresponding to the above.
- the metal salt (b) in the total solid content of the surface treatment solution needs to be 5 mass% or more.
- the content of the metal salt (b) there is no limit to increasing the content of the metal salt (b), but if the content of the metal salt (b) is too high, it will adhere to the coating film in applications such as automobiles.
- the content of the metal salt (b) in the total solid content of the surface treatment liquid is preferably 44% by mass or less, since the corrosion resistance and the corrosion resistance after coating deteriorate. It is more preferable that the content is not more than mass %.
- the preferable conditions for this surface treatment solution are as follows, and the reason is the same as the reason for the high-strength galvanized steel sheet described above.
- the metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum.
- the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group.
- the metal salt (b) is aluminum dihydrogen tripolyphosphate.
- Conductive particles and solid lubricant particles are not included. Preferably, it does not contain a particle component other than the metal salt (b).
- the solvent contains only the organic resin (a) and the metal salt (b).
- high-strength zinc having a tensile strength of 1180 MPa or more which has a coating containing the coating (x) on the surface of a galvanized steel sheet having a tensile strength of 1180 MPa or more (however, including galvannealed steel sheet).
- a high-strength galvanized steel sheet has excellent delayed fracture resistance. Furthermore, it has good corrosion resistance after painting.
- the high-strength galvanized steel sheet according to the second embodiment of the present invention has an inorganic coating and a coating including the coating (x) on the surface of the steel.
- the high-strength galvanized steel sheet has a predetermined inorganic coating on the surface of a galvanized steel sheet (including an alloyed hot-dip galvanized steel sheet) having a tensile strength of 1180 MPa or more, and further has the above-mentioned structure thereon. It has a film (x).
- the configuration other than the inorganic film is the same as that of the above-described first embodiment, and thus detailed description thereof will be omitted.
- the inorganic coating formed on the surface of the galvanized steel sheet contains at least one type ((c) component) selected from silane compounds and zirconium compounds.
- the component (c) is not particularly limited, but as the silane compound, a silane compound having a functional group, for example, a silane having a vinyl group, an epoxy group, a methacryl group, an acryl group, an amino group, a mercapto group, an isocyanate group, or the like.
- zirconium compounds include zirconium chloride, zirconyl chloride, zirconium sulfate, zirconyl sulfate, zirconium nitrate, zirconyl nitrate, zirconium hydrofluoric acid, zirconyl bromide, zirconyl acetate, zirconyl carbonate, and ammonium zirconium carbonate.
- the amount of the component (c) deposited on one surface of the steel sheet is preferably 200 to 500 mg/m 2 .
- the coating film adhesion can be more easily enhanced.
- Fluorescent X-ray analysis is an example of a method for measuring the amount of the component (c) deposited on one side of the steel sheet. Specifically, it can be calculated by irradiating the surface of the film with X-rays, measuring the intensity of fluorescent X-rays of the metal element contained in the component (c), and comparing it with a calibration curve.
- the method for producing the high-strength galvanized steel sheet of the present embodiment includes a step of forming an inorganic film on the surface of the galvanized steel sheet, and a step of forming a film (x) on the surface of the inorganic film formed in the step There is a method.
- a surface treatment liquid surface treatment liquid for forming an inorganic coating
- a solvent mainly water
- any coating means such as a roll coater (3 roll method, 2 roll method, etc.), a squeeze coater, a die coater or the like may be used. It is also possible to adjust the coating amount, make the appearance uniform, and make the film thickness uniform by an air knife method or a roll squeezing method after the coating treatment using a squeeze coater, the dipping treatment, and the spray treatment.
- the method of heating and drying the surface treatment liquid that is attached to the surface of the galvanized steel sheet and coated is arbitrary, and for example, a dryer, a hot-air stove, a high-frequency induction heating furnace, an infrared furnace, or the like can be used.
- a film (x) is formed on the surface of the inorganic film formed on the surface of the galvanized steel sheet as described above.
- the method of forming the film (x) can be the same as in the above-described first embodiment.
- the surface of the galvanized steel sheet (including the galvannealed steel sheet) having a tensile strength of 1180 MPa or more has a predetermined inorganic coating, and further has the above-mentioned coating (x) on the surface of 1180 MPa or more.
- a high-strength galvanized steel sheet having tensile strength can be manufactured. Such a high-strength galvanized steel sheet has excellent delayed fracture resistance. Further, it has good coating film adhesion.
- Example 1 As a galvanized steel sheet as a base material, the composition of the base steel sheet is C: 0.18% by mass, Si: 1.0% by mass, Mn: 3.0% by mass, P: 0.007% by mass, S:0.
- These galvanized steel sheets were immersed in toluene and subjected to ultrasonic cleaning for 5 minutes to remove the rust preventive oil, and then a resin film was formed on the surface.
- A1 to A4 were used as the organic resin (organic resin (a)) for the resin film, and a surface treatment liquid containing one of the organic resins and a predetermined metal salt (metal salt (b)) (in some Comparative Examples
- a surface treatment solution containing only organic resin is applied to the surface of the galvanized steel sheet by any one of a coating method (bar coat), a spray method, and a dipping method (and roll squeezing), and then the reached plate temperature is 120°C.
- a resin film was formed by heating with an induction heater so that A1: Epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., trade name: jER1009) A2: Acrylic resin (manufactured by DIC Corporation, trade name: 40-418EF) A3: Urethane resin (Dainippon Paint Co., Ltd., trade name: V Top RC Clear) A4: Fluororesin (Asahi Glass Co., Ltd., trade name: Lumiflon LF552)
- the cross section obtained by FIB processing is observed by SEM, and the thickness of the resin film (thickness from the zinc-plated steel plate surface of the base material to the surface of the resin film is observed at three locations in an arbitrary field of view).
- the average value thereof was taken as the film thickness.
- other particle components particle components other than the metal salt (b)
- SUS powder manufactured by Epson Atomix Co., Ltd.
- titanium nitride particles manufactured by Nippon Shinkin Co., Ltd.
- the delayed fracture resistance test piece thus produced was subjected to a combined cycle corrosion test consisting of dry, wet, and salt water immersion steps specified in SAE J2334 defined by the American Society of Automotive Engineers (see FIG. 2). Was carried out for up to 40 cycles. Before the salt water immersion step of each cycle, the presence or absence of cracks was visually inspected and the crack generation cycle was measured. In addition, this test was carried out by three samples for each high-strength galvanized steel sheet, and the average value was evaluated. The evaluation was performed based on the number of cycles according to the following criteria. In addition, the number of crack generation cycles of more than 40 in Table 3 indicates that no crack occurred in the results of this example.
- ⁇ and ⁇ were evaluated as acceptable (excellent in delayed fracture resistance), and ⁇ and ⁇ were evaluated as unacceptable (inferior in delayed fracture resistance).
- ⁇ More than 40 cycles ⁇ : 30 cycles or more, 40 cycles or less ⁇ : 10 cycles or more, less than 30 cycles ⁇ : less than 10 cycles
- the corrosion resistance test piece subjected to this electrodeposition coating was subjected to a combined cycle corrosion test (see Fig. 2) consisting of dry, wet, and salt water immersion steps specified in SAE J2334 defined by the American Society of Automotive Engineers. After the cycle, the corrosion resistance after coating was evaluated by the following procedure. (1) Punch out the spot weld and disassemble the mating structure (2) Peel off the coating (Neos'Deathcoat 300' 15 minutes immersion) (3) Plating and rust removal (diluted hydrochloric acid immersion) (4) Maximum erosion depth generated in the mating structure is measured with a point micrometer
- the corrosion resistance after coating was evaluated as follows by calculating the maximum erosion depth ratio (A) when the maximum erosion depth of the galvanized steel sheet having no resin film formed on its surface was set to 1.
- the No. 1 steel plate is a comparative example in which a resin film is not formed on the surface of the base material (hot dip galvanized steel plate) (comparative example of the hot dip galvanized steel plate), but It can be seen that delayed fracture has occurred and resistance to delayed fracture is low.
- a surface treatment solution prepared by mixing epoxy resin (A1) with aluminum dihydrogen tripolyphosphate as a metal salt (b) was applied to the surface of the hot dip galvanized steel plate by a coating method (bar coat).
- bar coat a coating method
- the No. 2 steel plate is an example in which the surface treatment liquid of the epoxy resin (A1) to which the metal salt (b) has not been added is similarly applied to form a resin film.
- the No. 2 steel plate to which the metal salt (b) is not added and the No. 3 and No. 4 steel plates in which the content of the metal salt (b) is below the range of the present invention have a resin film.
- the delayed fracture resistance is slightly improved as compared to the No. 1 steel sheet that is not formed, the delayed fracture resistance is inferior to the steel sheets of the invention examples.
- the steel sheet No. 15 in which the content of the metal salt (b) exceeds the preferred range of the present invention has lower corrosion resistance after painting than the steel sheets No. 5 to No. 14, and therefore the normal level.
- the No. 16 and No. 17 steel plates are examples of inventions in which the film forming method of the resin film is changed from that of the No. 11 steel plate, but both have excellent delayed fracture resistance and corrosion resistance after painting. Is also good.
- the steel sheets No. 18 to No. 31 are examples of inventions in which the type of the metal salt (b) mixed with the epoxy resin (A1) is changed, and all have excellent delayed fracture resistance and, after coating, Corrosion resistance is also good.
- the steel plates No. 32 to No. 37 are examples in which the film thickness of the resin film is changed.
- the steel sheets No. 33 to No. 37 having a film thickness within the range of the present invention all have excellent delayed fracture resistance and good corrosion resistance after coating.
- the No. 32 steel sheet having a resin film thickness below the range of the present invention is inferior in delayed fracture resistance to the invention examples No. 33 to No. 37 steel sheets.
- the corrosion resistance after painting is inferior.
- the steel plate No. 37 having a resin film thickness exceeding the preferred range of the present invention cannot be joined without being energized during spot welding, so there is no particular problem in applications where weldability is not required, but weldability is It can be said that it is not suitable for the required use.
- the steel sheets No. 38 to No. 40 are examples of inventions in which the type of organic resin is changed, but all have excellent delayed fracture resistance and good corrosion resistance after painting.
- No. 41 and No. 42 are, in addition to the metal salt (b) (aluminum dihydrogen tripolyphosphate) defined by the present invention, other particle components having a maximum particle size equal to or larger than the film thickness and having a large particle size (conductivity Comparative Example in which particles such as SUS powder and titanium nitride particles) are added to the film, but the delayed fracture resistance is inferior to the invention example No. 11 steel sheet.
- No. 43 and No. 44 are examples of inventions using an electrogalvanized steel sheet and a galvannealed steel sheet, respectively, as the base material, but both have excellent delayed fracture resistance and corrosion resistance after painting. It is good.
- Example 2 As a galvanized steel sheet as a base material, the composition of the base steel sheet is C: 0.18% by mass, Si: 1.0% by mass, Mn: 3.0% by mass, P: 0.007% by mass, S:0.
- a hot-dip galvanized steel sheet having a tensile strength of 1480 MPa and a plate thickness of 1.6 mm was used, which was composed of 0.0005% by mass, the balance Fe and unavoidable impurities.
- the hot-dip galvanized steel sheet was immersed in toluene and ultrasonically cleaned for 5 minutes to remove the rust preventive oil, and then an inorganic film was first formed on the surface and then a resin film was formed.
- a surface treatment liquid containing a silane compound or a zirconium compound shown in Tables 4 and 5 as a component (c) for forming an inorganic film on the surface of a galvanized steel sheet by a coating method using a bar coating method.
- An inorganic film was formed by heating with an induction heater so that the reached plate temperature was 120°C.
- the amount of the component (c) deposited on one surface was measured by irradiating the surface of the film with X-rays, measuring the intensity of the fluorescent X-ray of the metal element contained in the component (c), and comparing it with the calibration curve. ..
- the resin film was formed on the surface of the inorganic film formed as described above in the same manner as in Example 1. Further, the film thickness of the resin film was measured by the same method as in Example 1. As the other particle components, those similar to those in Example 1 were used.
- the coating film adhesion test was performed on the test piece for coating film adhesion test, which had been subjected to this electrodeposition coating, in the following procedure.
- (3) A cellophane tape ((registered trademark), manufactured by NICHIBAN, product number CT-24) is strongly pressure-bonded to the cross-cut portion, and the end of the tape is peeled off at an angle of 45°. (4) Check the state of the grid
- the coating film adhesion was evaluated as follows by measuring the number (N) of the grids from which the coating film was peeled off in the grid of the grid and confirming the state of the coating film.
- N the number of the grids from which the coating film was peeled off in the grid of the grid.
- the steel plate of No. 51 is a comparative example in which a resin film is not formed on the surface of the base material (hot dip galvanized steel plate) (comparative example of the hot-dip galvanized steel plate), but delayed fracture occurs early and is delayed. It can be seen that the destructiveness is low.
- the steel sheets of Nos. 53 to 65 have an inorganic coating containing zirconium ammonium carbonate formed on the surface of a galvanized steel sheet by a coating method, and an epoxy resin (A1) as a metal salt (b) of dihydrogen polyphosphate as an upper layer thereon.
- an epoxy resin (A1) as a metal salt (b) of dihydrogen polyphosphate as an upper layer thereon.
- a surface treatment liquid mixed with aluminum is applied by a coating method (bar coating) to form a film.
- the steel plate No. 52 is an example in which the surface treatment liquid of the epoxy resin (A1) to which the metal salt (b) has not been added is similarly applied to form a film.
- the coating film adhesion is deteriorated as compared with No. 55 to No. 64 steel sheet, There is no particular problem in applications where a high level of coating film adhesion is required, but it can be said that it is unsuitable for applications where a particularly high level of coating film adhesion is required.
- the steel sheets No. 66 and 67 are examples of inventions in which the film forming method of the resin coating is changed from that of the steel sheet No. 61, but both have excellent delayed fracture resistance and coating film adhesion. It is good.
- Steel sheets No. 68 to 81 are examples of the invention in which the type of the metal salt (b) mixed with the epoxy resin (A1) is changed, and all of them have excellent delayed fracture resistance and coating film adhesion. Is also good.
- the steel sheets No. 82 to 87 are examples in which the film thickness of the resin film is changed.
- the steel sheets No. 83 to No. 87 having a film thickness within the range of the present invention all have excellent delayed fracture resistance and good coating film adhesion.
- the No. 82 steel sheet having a resin film thickness below the range of the present invention is inferior in delayed fracture resistance to the invention examples No. 83 to No. 87 steel sheet.
- the steel plate of No. 87 in which the film thickness of the resin film exceeds the preferred range of the present invention cannot be joined without energization during spot welding, so there is no particular problem in applications where weldability is not required, but weldability is It can be said that it is not suitable for the required use.
- the steel sheets Nos. 88 to 90 are examples of inventions in which the type of organic resin is changed, but all of them have excellent delayed fracture resistance and good coating adhesion.
- Nos. 91 and 92 are, in addition to the metal salt (b) (aluminum dihydrogen tripolyphosphate) defined by the present invention, other particle components having a maximum particle size equal to or larger than the film thickness and having a large particle size (conductive particles.
- metal salt (b) aluminum dihydrogen tripolyphosphate
- conductive particles conductive particles.
- This is a comparative example in which a certain SUS powder and titanium nitride particles) are added to the film, but the delayed fracture resistance is inferior to the steel sheet of No. 61 which is an example of the invention.
- No. 93 is an example of the invention in which the resin coating was directly formed on the hot-dip galvanized steel sheet without forming the lower inorganic coating, and although the delayed fracture resistance was excellent, the coating adhesion was poor. is there.
- Nos. 94 to 98 are invention examples in which the amount of the lower layer zirconium ammonium carbonate compound deposited on one side of the steel sheet was changed, but the amount of zirconium ammonium carbonate deposited on one side of the steel sheet was below the preferred range of the present invention.
- the .94 steel plate is inferior in coating film adhesion to Nos. 95 to 97.
- Nos. 99 to 101 are examples of the invention in which the compound contained in the lower inorganic coating was changed, and all of them showed good delayed fracture resistance and good coating adhesion.
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Abstract
Provided is a high-strength zinc-plated steel sheet having excellent delayed fracture resistance. A high-strength zinc-plated steel sheet having a coating film (x) on a surface thereof, wherein the coating film (x) contains an organic resin (a) and a metal salt (b) containing at least one group selected from a phosphate group, a phosphite group, a silicate group and a molybdate group, and does not contain a particulate component other than the metal salt (b) and having a largest particle diameter equal to or larger than the film thickness of the coating film (x). The metal salt (b) and Zn together form a chelate complex and, as the result, a dense passive coating film is formed on the surface of the steel sheet; the pH value falls within the range from 8 to 11 steadily due to the pH buffering effect of an ion containing the metal salt (b) and, as the result, the dissolution of Zn can be prevented and the generation of hydrogen on the base metal can be suppressed; and the coating layer (x) does not contain a microparticulate component other than the metal salt (b) and having a larger particle diameter and, therefore, it is possible to prevent the interface between each of the particles and the coating film (x) from becoming the point of origin of corrosion. As a result, the invasion of hydrogen into the inside of the steel sheet can be prevented and excellent delayed fracture resistance can be achieved.
Description
本発明は、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板およびその製造方法並びに表面処理液に関する。本発明は、主として自動車、建材用の強度部材に適した鋼板であって、耐遅れ破壊性に優れた１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板およびその製造技術に関する。
The present invention relates to a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, a method for manufacturing the same, and a surface treatment liquid. TECHNICAL FIELD The present invention relates to a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which is a steel sheet suitable mainly for strength members for automobiles and building materials, and has excellent delayed fracture resistance, and a manufacturing technique thereof.
近年、自動車のＣＯ２排出量の低減および安全性確保の観点から、自動車に用いられる鋼板は高強度化が図られており、引張強度が１１８０ＭＰａを超えるような高強度鋼板の適用も進められている。
In recent years, from the viewpoint of reducing CO 2 emission of automobiles and ensuring safety, steel sheets used for automobiles have been strengthened, and application of high-strength steel sheets having a tensile strength of more than 1180 MPa has been promoted. There is.
しかしながら、強度の高い鋼材では、遅れ破壊が発生することが知られており、特に高張力ボルトが使用環境中において破断することが、しばしば報告されている。遅れ破壊とは、高強度鋼材が静的な負荷応力（引張り強さ以下の負荷応力）を受けた状態で、ある時間が経過したとき、外見上はほとんど塑性変形を伴うことなく、突然脆性的な破壊が生じる現象である。遅れ破壊は、鋼材強度が高くなるほど生じやすく、特に引張強度が１１８０ＭＰａ以上の高強度鋼でより顕著となる。
However, it is known that delayed fracture occurs in steel materials with high strength, and it is often reported that high-strength bolts break, especially in the use environment. Delayed fracture is a state in which high-strength steel is subjected to static load stress (load stress of tensile strength or less), and when a certain time has elapsed, it appears to be suddenly brittle with almost no plastic deformation. This is a phenomenon in which various destructions occur. Delayed fracture is more likely to occur as the strength of the steel material becomes higher, and becomes more prominent particularly in high-strength steel having a tensile strength of 1180 MPa or more.
鋼板の場合、遅れ破壊は、プレス加工により所定の形状に成形したときの残留応力と、応力集中部における鋼の水素脆性により生じるものであることが知られている。この水素脆性の原因となる水素は、ほとんどの場合、外部環境から鋼中に侵入、拡散した水素であると考えられており、代表的には、鋼板の腐食の際に発生した水素が鋼中に侵入、拡散したものがある。
In the case of steel sheets, it is known that delayed fracture is caused by residual stress when formed into a predetermined shape by press working and hydrogen embrittlement of the steel in the stress concentrated portion. In most cases, the hydrogen that causes hydrogen embrittlement is considered to be hydrogen that has penetrated and diffused into the steel from the external environment.Typically, hydrogen generated during corrosion of steel sheets is Some have invaded and spread.
高強度鋼板におけるこのような遅れ破壊を防止するために、例えば、特許文献１では、鋼板の組織や成分を調整することにより、遅れ破壊感受性を弱める検討がなされている。また、特許文献２では、遅れ破壊を防止する高強度合金化溶融亜鉛めっき鋼板に関する検討がなされている。
In order to prevent such delayed fracture in high-strength steel sheets, for example, in Patent Document 1, a study is made to weaken the delayed fracture sensitivity by adjusting the structure and composition of the steel sheet. Further, in Patent Document 2, a study on a high-strength galvannealed steel sheet for preventing delayed fracture is made.
しかし、特許文献１の手法では、外部環境から鋼板内部に侵入する水素量は変化しないため、遅れ破壊の発生を遅らせることは可能であるが、遅れ破壊自体を防止することはできない。また、特許文献２の手法では、亜鉛めっきの犠牲防食効果により素地への水素の侵入が促進されるため、優れた耐遅れ破壊性は期待できない。
However, with the method of Patent Document 1, since the amount of hydrogen that penetrates into the steel sheet from the external environment does not change, it is possible to delay the occurrence of delayed fracture, but it is not possible to prevent delayed fracture itself. Further, in the method of Patent Document 2, since the penetration of hydrogen into the substrate is promoted by the sacrificial anticorrosive effect of zinc plating, excellent delayed fracture resistance cannot be expected.
したがって本発明の目的は、以上のような従来技術の課題を解決し、耐遅れ破壊性に優れた１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板を提供することにある。
Therefore, an object of the present invention is to solve the problems of the prior art as described above and to provide a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which is excellent in delayed fracture resistance.
また、本発明の他の目的は、上記のような優れた特性を有する１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法および表面処理液を提供することにある。
なお、以下、本発明の「１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板」を、単に「高強度亜鉛めっき鋼板」ともいう。 Another object of the present invention is to provide a method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which has the above-mentioned excellent properties, and a surface treatment liquid.
Note that, hereinafter, the "high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more" of the present invention is also simply referred to as "high-strength galvanized steel sheet".
なお、以下、本発明の「１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板」を、単に「高強度亜鉛めっき鋼板」ともいう。 Another object of the present invention is to provide a method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which has the above-mentioned excellent properties, and a surface treatment liquid.
Note that, hereinafter, the "high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more" of the present invention is also simply referred to as "high-strength galvanized steel sheet".
本発明者らは、使用環境中における亜鉛めっき鋼板の遅れ破壊を防止するために、鋼板内部に侵入する水素量を低減する手段について鋭意検討および研究を重ねた。その結果、亜鉛めっき鋼板の表面に特定の金属塩を含有し且つ他の特定の粒子成分を含まない樹脂皮膜を形成することにより、鋼板内部への水素侵入が抑制され、優れた耐遅れ破壊性が得られることを見出した。
The present inventors have conducted extensive studies and research on means for reducing the amount of hydrogen that penetrates into the steel sheet in order to prevent delayed fracture of the galvanized steel sheet in the use environment. As a result, by forming a resin film containing a specific metal salt and not containing other specific particle components on the surface of the galvanized steel sheet, hydrogen intrusion into the steel sheet is suppressed, and excellent delayed fracture resistance It was found that
本発明は、以上のような知見に基づきなされたものであり、その要旨は以下のとおりである。
[1]引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む。）の表面に皮膜（x）を含む皮膜を有し、該皮膜（x）は、有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ前記金属塩（b）以外には最大粒子径が該皮膜（x）の膜厚以上の粒子成分を含有せず、膜厚が０．３μｍ以上であり、皮膜（x）中での金属塩（b）の含有量が５質量％以上である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［2］上記［1］の高強度亜鉛めっき鋼板において、金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［3］上記［1］または［2］の高強度亜鉛めっき鋼板において、金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［4］上記［1］～［3］のいずれかの高強度亜鉛めっき鋼板において、金属塩（b）の鋼板片面あたりの付着量が５０ｍｇ／ｍ２以上である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［5］上記［1］～［4］のいずれかの高強度亜鉛めっき鋼板において、金属塩（b）がトリポリリン酸二水素アルミニウムであり、皮膜（x）の膜厚が１．０μｍ以上であり、皮膜（x）中でのトリポリリン酸二水素アルミニウムの含有量が１７～４５質量％である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［6］上記［1］～［5］のいずれかの高強度亜鉛めっき鋼板において、皮膜（x）は、導電性粒子および固体潤滑剤粒子を含有しない、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［7］上記［1］～［6］のいずれかの高強度亜鉛めっき鋼板において、皮膜（x）は、金属塩（b）以外の粒子成分を含有しない、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［8］上記［1］～［7］のいずれかの高強度亜鉛めっき鋼板において、皮膜（x）中に存在する金属塩（b）の含有量が４０質量％以下である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［9］上記［1］～［8］のいずれかの高強度亜鉛めっき鋼板において、皮膜（x）の膜厚が４．０μｍ以下である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 The present invention has been made based on the above findings, and its gist is as follows.
[1] A galvanized steel sheet having a tensile strength of 1180 MPa or more (however, including galvannealed steel sheet) has a coating containing the coating (x), and the coating (x) is an organic resin (a). ) And a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group, and a molybdic acid group, and the maximum particle size other than the metal salt (b) is The coating film (x) does not contain a particle component having a thickness equal to or larger than the film thickness, the film thickness is 0.3 μm or more, and the content of the metal salt (b) in the film (x) is 5% by mass or more, A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more.
[2] In the high-strength galvanized steel sheet according to [1], the metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum, and has a tensile strength of 1180 MPa or more. High strength galvanized steel sheet.
[3] In the high-strength galvanized steel sheet according to [1] or [2], the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group, and a silicic acid group. A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more.
[4] In the high-strength galvanized steel sheet according to any one of [1] to [3], the metal salt (b) has a tensile strength of 1180 MPa or more, which is 50 mg/m 2 or more per one side of the steel sheet. High strength galvanized steel sheet.
[5] In the high-strength galvanized steel sheet according to any one of the above [1] to [4], the metal salt (b) is aluminum dihydrogen tripolyphosphate, and the film thickness of the film (x) is 1.0 μm or more. A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, wherein the content of aluminum dihydrogen tripolyphosphate in the film (x) is 17 to 45% by mass.
[6] In the high-strength galvanized steel sheet according to any one of the above [1] to [5], the coating (x) does not contain conductive particles and solid lubricant particles, and has high strength zinc having a tensile strength of 1180 MPa or more. Plated steel sheet.
[7] In the high-strength galvanized steel sheet according to any one of the above [1] to [6], the coating (x) has high tensile strength of 1180 MPa or more, containing no particle component other than the metal salt (b). Galvanized steel sheet.
[8] In the high-strength galvanized steel sheet according to any one of the above [1] to [7], the content of the metal salt (b) present in the coating (x) is 40% by mass or less, and a tensile strength of 1180 MPa or more. High strength galvanized steel sheet with strength.
[9] The high-strength galvanized steel sheet according to any one of the above [1] to [8], which has a film thickness of the film (x) of 4.0 μm or less and a tensile strength of 1180 MPa or more.
[1]引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む。）の表面に皮膜（x）を含む皮膜を有し、該皮膜（x）は、有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ前記金属塩（b）以外には最大粒子径が該皮膜（x）の膜厚以上の粒子成分を含有せず、膜厚が０．３μｍ以上であり、皮膜（x）中での金属塩（b）の含有量が５質量％以上である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［2］上記［1］の高強度亜鉛めっき鋼板において、金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［3］上記［1］または［2］の高強度亜鉛めっき鋼板において、金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［4］上記［1］～［3］のいずれかの高強度亜鉛めっき鋼板において、金属塩（b）の鋼板片面あたりの付着量が５０ｍｇ／ｍ２以上である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［5］上記［1］～［4］のいずれかの高強度亜鉛めっき鋼板において、金属塩（b）がトリポリリン酸二水素アルミニウムであり、皮膜（x）の膜厚が１．０μｍ以上であり、皮膜（x）中でのトリポリリン酸二水素アルミニウムの含有量が１７～４５質量％である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［6］上記［1］～［5］のいずれかの高強度亜鉛めっき鋼板において、皮膜（x）は、導電性粒子および固体潤滑剤粒子を含有しない、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［7］上記［1］～［6］のいずれかの高強度亜鉛めっき鋼板において、皮膜（x）は、金属塩（b）以外の粒子成分を含有しない、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［8］上記［1］～［7］のいずれかの高強度亜鉛めっき鋼板において、皮膜（x）中に存在する金属塩（b）の含有量が４０質量％以下である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［9］上記［1］～［8］のいずれかの高強度亜鉛めっき鋼板において、皮膜（x）の膜厚が４．０μｍ以下である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 The present invention has been made based on the above findings, and its gist is as follows.
[1] A galvanized steel sheet having a tensile strength of 1180 MPa or more (however, including galvannealed steel sheet) has a coating containing the coating (x), and the coating (x) is an organic resin (a). ) And a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group, and a molybdic acid group, and the maximum particle size other than the metal salt (b) is The coating film (x) does not contain a particle component having a thickness equal to or larger than the film thickness, the film thickness is 0.3 μm or more, and the content of the metal salt (b) in the film (x) is 5% by mass or more, A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more.
[2] In the high-strength galvanized steel sheet according to [1], the metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum, and has a tensile strength of 1180 MPa or more. High strength galvanized steel sheet.
[3] In the high-strength galvanized steel sheet according to [1] or [2], the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group, and a silicic acid group. A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more.
[4] In the high-strength galvanized steel sheet according to any one of [1] to [3], the metal salt (b) has a tensile strength of 1180 MPa or more, which is 50 mg/m 2 or more per one side of the steel sheet. High strength galvanized steel sheet.
[5] In the high-strength galvanized steel sheet according to any one of the above [1] to [4], the metal salt (b) is aluminum dihydrogen tripolyphosphate, and the film thickness of the film (x) is 1.0 μm or more. A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, wherein the content of aluminum dihydrogen tripolyphosphate in the film (x) is 17 to 45% by mass.
[6] In the high-strength galvanized steel sheet according to any one of the above [1] to [5], the coating (x) does not contain conductive particles and solid lubricant particles, and has high strength zinc having a tensile strength of 1180 MPa or more. Plated steel sheet.
[7] In the high-strength galvanized steel sheet according to any one of the above [1] to [6], the coating (x) has high tensile strength of 1180 MPa or more, containing no particle component other than the metal salt (b). Galvanized steel sheet.
[8] In the high-strength galvanized steel sheet according to any one of the above [1] to [7], the content of the metal salt (b) present in the coating (x) is 40% by mass or less, and a tensile strength of 1180 MPa or more. High strength galvanized steel sheet with strength.
[9] The high-strength galvanized steel sheet according to any one of the above [1] to [8], which has a film thickness of the film (x) of 4.0 μm or less and a tensile strength of 1180 MPa or more.
［10］引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む。）の表面に皮膜（x）を含む皮膜を有する１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法であって、該皮膜（x）は、有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ前記金属塩（b）以外には最大粒子径が該皮膜（x）の膜厚以上の粒子成分を含有せず、膜厚が０．３μｍ以上であり、皮膜（x）中での金属塩（b）の含有量が５質量％以上であり、前記皮膜（x）を、前記有機樹脂（a）と、前記金属塩（b）を含有し、且つ前記金属塩（b）以外には最大粒子径が形成すべき前記皮膜（x）の膜厚以上の粒子成分を含有しない表面処理液を、前記皮膜（x）を形成すべき表面に付着させることにより形成する、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［11］上記［10］の製造方法において、金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［12］上記［10］または［11］の製造方法において、金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［13］上記［10］～［12］のいずれかの製造方法において、金属塩（b）の鋼板片面あたりの付着量が５０ｍｇ／ｍ２以上である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［14］上記［10］～［13］のいずれかの製造方法において、金属塩（b）がトリポリリン酸二水素アルミニウムであり、皮膜（x）の膜厚が１．０μｍ以上であり、皮膜（x）中でのトリポリリン酸二水素アルミニウムの含有量が１７～４５質量％である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［15］上記［10］～［14］のいずれかの製造方法において、皮膜（x）は、導電性粒子および固体潤滑剤粒子を含有しない、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［16］上記［10］～［15］のいずれかの製造方法において、表面処理液は、金属塩（b）以外の粒子成分を含有しない、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［17］上記［10］～［16］のいずれかの製造方法において、皮膜（x）中に存在する金属塩（b）の含有量が４０質量％以下である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［18］上記［10］～［17］のいずれかの製造方法において、皮膜（x）の膜厚が４．０μｍ以下である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 [10] A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which has a coating containing a coating (x) on the surface of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including a galvannealed steel sheet). In the production method, the film (x) comprises an organic resin (a) and a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group and a molybdic acid group. In addition to the metal salt (b), it does not contain a particle component having a maximum particle size of at least the film thickness of the coating (x), and has a film thickness of 0.3 μm or more. Content of the metal salt (b) of 5% by mass or more, the coating film (x) contains the organic resin (a) and the metal salt (b), and other than the metal salt (b) Is formed by adhering to the surface where the coating (x) is to be formed, a surface treatment liquid that does not contain a particle component having a maximum particle size that is greater than or equal to the thickness of the coating (x) to be formed. A method for producing a high-strength galvanized steel sheet having tensile strength.
[11] In the production method of the above-mentioned [10], the metal salt (b) is a metal salt containing at least one of an alkali metal, an alkaline earth metal and aluminum, and has high tensile strength of 1180 MPa or more. Manufacturing method of galvanized steel sheet.
[12] In the production method of the above-mentioned [10] or [11], the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group, 1180 MPa or more. Of manufacturing a high-strength galvanized steel sheet having the above tensile strength.
[13] The high-strength zinc having a tensile strength of 1180 MPa or more, in which the amount of the metal salt (b) deposited on one surface of the steel sheet is 50 mg/m 2 or more, in the manufacturing method according to any one of [10] to [12] above. Manufacturing method of plated steel sheet.
[14] In the production method according to any one of the above [10] to [13], the metal salt (b) is aluminum dihydrogen tripolyphosphate, and the film (x) has a film thickness of 1.0 μm or more. A method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, wherein the content of aluminum dihydrogen tripolyphosphate in x) is 17 to 45% by mass.
[15] In the manufacturing method according to any one of the above [10] to [14], the coating (x) is a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more that does not contain conductive particles and solid lubricant particles. Production method.
[16] In the manufacturing method according to any one of the above [10] to [15], the surface treatment liquid is a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more that does not contain particle components other than the metal salt (b). Production method.
[17] In the production method according to any one of the above [10] to [16], the film (x) has a tensile strength of 1180 MPa or more, in which the content of the metal salt (b) is 40% by mass or less. Method for manufacturing high strength galvanized steel sheet.
[18] The method for producing a high-strength galvanized steel sheet according to any one of the above [10] to [17], wherein the film thickness of the coating (x) is 4.0 μm or less and which has a tensile strength of 1180 MPa or more.
［11］上記［10］の製造方法において、金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［12］上記［10］または［11］の製造方法において、金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［13］上記［10］～［12］のいずれかの製造方法において、金属塩（b）の鋼板片面あたりの付着量が５０ｍｇ／ｍ２以上である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［14］上記［10］～［13］のいずれかの製造方法において、金属塩（b）がトリポリリン酸二水素アルミニウムであり、皮膜（x）の膜厚が１．０μｍ以上であり、皮膜（x）中でのトリポリリン酸二水素アルミニウムの含有量が１７～４５質量％である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［15］上記［10］～［14］のいずれかの製造方法において、皮膜（x）は、導電性粒子および固体潤滑剤粒子を含有しない、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［16］上記［10］～［15］のいずれかの製造方法において、表面処理液は、金属塩（b）以外の粒子成分を含有しない、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［17］上記［10］～［16］のいずれかの製造方法において、皮膜（x）中に存在する金属塩（b）の含有量が４０質量％以下である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。
［18］上記［10］～［17］のいずれかの製造方法において、皮膜（x）の膜厚が４．０μｍ以下である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 [10] A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which has a coating containing a coating (x) on the surface of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including a galvannealed steel sheet). In the production method, the film (x) comprises an organic resin (a) and a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group and a molybdic acid group. In addition to the metal salt (b), it does not contain a particle component having a maximum particle size of at least the film thickness of the coating (x), and has a film thickness of 0.3 μm or more. Content of the metal salt (b) of 5% by mass or more, the coating film (x) contains the organic resin (a) and the metal salt (b), and other than the metal salt (b) Is formed by adhering to the surface where the coating (x) is to be formed, a surface treatment liquid that does not contain a particle component having a maximum particle size that is greater than or equal to the thickness of the coating (x) to be formed. A method for producing a high-strength galvanized steel sheet having tensile strength.
[11] In the production method of the above-mentioned [10], the metal salt (b) is a metal salt containing at least one of an alkali metal, an alkaline earth metal and aluminum, and has high tensile strength of 1180 MPa or more. Manufacturing method of galvanized steel sheet.
[12] In the production method of the above-mentioned [10] or [11], the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group, 1180 MPa or more. Of manufacturing a high-strength galvanized steel sheet having the above tensile strength.
[13] The high-strength zinc having a tensile strength of 1180 MPa or more, in which the amount of the metal salt (b) deposited on one surface of the steel sheet is 50 mg/m 2 or more, in the manufacturing method according to any one of [10] to [12] above. Manufacturing method of plated steel sheet.
[14] In the production method according to any one of the above [10] to [13], the metal salt (b) is aluminum dihydrogen tripolyphosphate, and the film (x) has a film thickness of 1.0 μm or more. A method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, wherein the content of aluminum dihydrogen tripolyphosphate in x) is 17 to 45% by mass.
[15] In the manufacturing method according to any one of the above [10] to [14], the coating (x) is a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more that does not contain conductive particles and solid lubricant particles. Production method.
[16] In the manufacturing method according to any one of the above [10] to [15], the surface treatment liquid is a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more that does not contain particle components other than the metal salt (b). Production method.
[17] In the production method according to any one of the above [10] to [16], the film (x) has a tensile strength of 1180 MPa or more, in which the content of the metal salt (b) is 40% by mass or less. Method for manufacturing high strength galvanized steel sheet.
[18] The method for producing a high-strength galvanized steel sheet according to any one of the above [10] to [17], wherein the film thickness of the coating (x) is 4.0 μm or less and which has a tensile strength of 1180 MPa or more.
［19］引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む。）の遅れ破壊を抑制するための皮膜（x）を含む皮膜を前記亜鉛めっき鋼板の表面に形成するための表面処理液であって、有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ前記金属塩（b）以外には最大粒子径が形成すべき前記皮膜（x）の膜厚以上の粒子成分を含有せず、全固形分中での前記金属塩（b）の含有割合が５質量％以上である、表面処理液。
[19] A film including a film (x) for suppressing delayed fracture of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including galvannealed steel sheet) is formed on the surface of the galvanized steel sheet. A surface treatment liquid for containing an organic resin (a) and a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group and a molybdic acid group, and Other than the metal salt (b), it does not contain a particle component having a maximum particle diameter of at least the film thickness of the film (x) to be formed, and the content ratio of the metal salt (b) in the total solid content is 5 A surface treatment liquid having a mass% or more.
［20］上記［1］～［9］のいずれかの高強度亜鉛めっき鋼板において、皮膜が、無機皮膜と前記無機皮膜上に形成された皮膜（x）を含み、前記無機皮膜は、シラン化合物、ジルコニウム化合物から選ばれる少なくとも１種（（c）成分）を含有し、前記（c）成分の鋼板片面あたりの付着量が２００～５００ｍｇ／ｍ２である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。
［21］上記［10］～［18］のいずれかの製造方法において、皮膜が、無機皮膜と前記無機皮膜上に形成された皮膜（x）を含み、シラン化合物、ジルコニウム化合物から選ばれる少なくとも１種（（c）成分）を含有する表面処理液を、前記亜鉛めっき鋼板に付着させることにより、前記（c）成分の鋼板片面あたりの付着量が２００～５００ｍｇ／ｍ２である前記無機皮膜を形成し、その後、前記無機皮膜の表面に前記皮膜（x）を形成する、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 [20] In the high-strength galvanized steel sheet according to any one of the above [1] to [9], the coating includes an inorganic coating and a coating (x) formed on the inorganic coating, and the inorganic coating is a silane compound. A high strength containing at least one selected from zirconium compounds (component (c)) and having a tensile strength of 1180 MPa or more, in which the amount of the component (c) deposited on one side of the steel sheet is 200 to 500 mg/m 2. Galvanized steel sheet.
[21] In the manufacturing method according to any one of the above [10] to [18], the coating includes an inorganic coating and a coating (x) formed on the inorganic coating, and at least one selected from a silane compound and a zirconium compound. By depositing a surface treatment solution containing a seed (component (c)) onto the galvanized steel sheet, the inorganic coating having an amount of component (c) deposited on one side of the steel sheet of 200 to 500 mg/m 2 is obtained. A method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which is formed and then the coating (x) is formed on the surface of the inorganic coating.
［21］上記［10］～［18］のいずれかの製造方法において、皮膜が、無機皮膜と前記無機皮膜上に形成された皮膜（x）を含み、シラン化合物、ジルコニウム化合物から選ばれる少なくとも１種（（c）成分）を含有する表面処理液を、前記亜鉛めっき鋼板に付着させることにより、前記（c）成分の鋼板片面あたりの付着量が２００～５００ｍｇ／ｍ２である前記無機皮膜を形成し、その後、前記無機皮膜の表面に前記皮膜（x）を形成する、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 [20] In the high-strength galvanized steel sheet according to any one of the above [1] to [9], the coating includes an inorganic coating and a coating (x) formed on the inorganic coating, and the inorganic coating is a silane compound. A high strength containing at least one selected from zirconium compounds (component (c)) and having a tensile strength of 1180 MPa or more, in which the amount of the component (c) deposited on one side of the steel sheet is 200 to 500 mg/m 2. Galvanized steel sheet.
[21] In the manufacturing method according to any one of the above [10] to [18], the coating includes an inorganic coating and a coating (x) formed on the inorganic coating, and at least one selected from a silane compound and a zirconium compound. By depositing a surface treatment solution containing a seed (component (c)) onto the galvanized steel sheet, the inorganic coating having an amount of component (c) deposited on one side of the steel sheet of 200 to 500 mg/m 2 is obtained. A method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which is formed and then the coating (x) is formed on the surface of the inorganic coating.
本発明の高強度亜鉛めっき鋼板は、耐遅れ破壊性に優れる。
本発明の高強度亜鉛めっき鋼板は、亜鉛めっき表面に形成される特定の皮膜により、腐食抑制を通じて鋼板内部への水素の侵入が抑制され、遅れ破壊が効果的に抑制される優れた耐遅れ破壊性を有する。 The high-strength galvanized steel sheet of the present invention has excellent delayed fracture resistance.
The high-strength galvanized steel sheet of the present invention has an excellent delayed fracture resistance in which the specific coating formed on the galvanized surface suppresses the intrusion of hydrogen into the steel sheet through corrosion inhibition and effectively suppresses the delayed fracture. Have sex.
本発明の高強度亜鉛めっき鋼板は、亜鉛めっき表面に形成される特定の皮膜により、腐食抑制を通じて鋼板内部への水素の侵入が抑制され、遅れ破壊が効果的に抑制される優れた耐遅れ破壊性を有する。 The high-strength galvanized steel sheet of the present invention has excellent delayed fracture resistance.
The high-strength galvanized steel sheet of the present invention has an excellent delayed fracture resistance in which the specific coating formed on the galvanized surface suppresses the intrusion of hydrogen into the steel sheet through corrosion inhibition and effectively suppresses the delayed fracture. Have sex.
また、皮膜構成がより適正化された本発明の高強度亜鉛めっき鋼板は、優れた耐遅れ破壊性とともに、良好な塗装後耐食性を有する。
The high-strength galvanized steel sheet of the present invention, which has a more optimized film structure, has excellent delayed fracture resistance and good post-paint corrosion resistance.
また、皮膜構成がより適正化された本発明の高強度亜鉛めっき鋼板は、優れた耐遅れ破壊性とともに、良好な塗膜密着性を有する。
The high-strength galvanized steel sheet of the present invention, which has a more optimized coating structure, has excellent delayed fracture resistance and good coating adhesion.
また、本発明の高強度亜鉛めっき鋼板は、主として自動車、建材用の強度部材に適する。本発明の高強度亜鉛めっき鋼板は、鋼板の強度向上により鋼板の板厚を削減できるため、自動車分野、建材分野に適用する強度部材の重量削減が可能となる。
The high-strength galvanized steel sheet of the present invention is mainly suitable for strength members for automobiles and building materials. Since the high-strength galvanized steel sheet of the present invention can reduce the thickness of the steel sheet by improving the strength of the steel sheet, it is possible to reduce the weight of the strength member applied to the fields of automobiles and construction materials.
また、本発明の高強度亜鉛めっき鋼板の製造方法と表面処理液によれば、上記のような優れた特性を有する高強度亜鉛めっき鋼板を安定して製造することができる。
Further, according to the method for producing a high-strength galvanized steel sheet and the surface treatment solution of the present invention, it is possible to stably produce a high-strength galvanized steel sheet having the above-mentioned excellent properties.
以下、本発明について、実施形態を示して説明する。ただし、本発明は、以下の実施形態に限定されない。
Hereinafter, the present invention will be described by showing embodiments. However, the present invention is not limited to the following embodiments.
＜第一実施形態＞
本発明の第一実施形態にかかる高強度亜鉛めっき鋼板は、引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（合金化溶融亜鉛めっき鋼板を含む。）の表面に、皮膜（x）を有する。前記皮膜（x）は特定の金属塩を含有する。 <First embodiment>
The high-strength galvanized steel sheet according to the first embodiment of the present invention has a coating (x) on the surface of a galvanized steel sheet (including an alloyed hot-dip galvanized steel sheet) having a tensile strength of 1180 MPa or more. The film (x) contains a specific metal salt.
本発明の第一実施形態にかかる高強度亜鉛めっき鋼板は、引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（合金化溶融亜鉛めっき鋼板を含む。）の表面に、皮膜（x）を有する。前記皮膜（x）は特定の金属塩を含有する。 <First embodiment>
The high-strength galvanized steel sheet according to the first embodiment of the present invention has a coating (x) on the surface of a galvanized steel sheet (including an alloyed hot-dip galvanized steel sheet) having a tensile strength of 1180 MPa or more. The film (x) contains a specific metal salt.
本発明の高強度亜鉛めっき鋼板の下地（基質）となる鋼板（下地鋼板）は、引張強度が１１８０ＭＰａ以上の高強度鋼板であり、引張強度が１４８０ＭＰａ以上の高強度鋼板であることがより好ましい。引張強度が低い鋼板は、本質的に遅れ破壊が生じにくい。本発明の効果は、引張強度が低い鋼板でも発現されるが、引張強度が１１８０ＭＰａ以上の高強度鋼板で顕著に発現され、引張強度が１４８０ＭＰａ以上の高強度鋼板でより顕著に発現されるためである。下地鋼板の化学組成や鋼組織は特に限定されない。下地鋼板としては、自動車分野や建材分野などで用いられる、特に自動車分野などで多く用いられる引張強度が１１８０ＭＰａ以上の高強度鋼板が好ましく、引張強度が１４８０ＭＰａ以上の高強度鋼板がさらに好ましい。
The steel plate (base steel plate) that serves as the base (substrate) of the high-strength galvanized steel plate of the present invention is a high-strength steel plate having a tensile strength of 1180 MPa or more, and more preferably a high-strength steel plate having a tensile strength of 1480 MPa or more. Steel sheets with low tensile strength are essentially less prone to delayed fracture. The effect of the present invention is exhibited even in a steel sheet having a low tensile strength, but is remarkably exhibited in a high strength steel sheet having a tensile strength of 1180 MPa or more, and is more remarkably exhibited in a high strength steel sheet having a tensile strength of 1480 MPa or more. is there. The chemical composition and steel structure of the base steel sheet are not particularly limited. As the base steel sheet, a high-strength steel sheet having a tensile strength of 1180 MPa or more, which is often used in an automobile field, a construction material field, and the like, particularly in an automobile field, is preferable, and a high-strength steel sheet having a tensile strength of 1480 MPa or more is more preferable.
本発明において、下地鋼板として好ましく用いられる高強度鋼板は、所望の引張強度を有するものであれば、いかなる組成および組織を有するものでもよい。かかる高強度鋼板としては、機械特性などの諸特性を向上させるために、例えば、Ｃ、Ｎなどの侵入型固溶元素およびＳｉ、Ｍｎ、Ｐ、Ｃｒなどの置換型固溶元素の添加による固溶体強化、Ｔｉ、Ｎｂ、Ｖ、Ａｌなどの炭・窒化物による析出強化、Ｗ、Ｚｒ、Ｈｆ、Ｃｏ、Ｂ、Ｃｕ、希土類元素などの強化元素の添加などの化学組成的改質、再結晶の起こらない温度で回復焼きなましすることによる強靭化あるいは完全に再結晶させずに未再結晶領域を残す部分再結晶強化、ベイナイトやマルテンサイト単相化あるいはフェライトとこれら変態組織の複合組織化といった変態組織による強化、フェライト粒径をｄとしたときのHall-Petchの式：σ＝σ０+ｋｄ-1/2（式中σ：応力、σ０，ｋ：材料定数）で表される細粒化強化、圧延などによる加工強化といった組織的ないし構造的改質を単独でまたは複数組み合わせて施した高強度鋼板を用いることができる。
In the present invention, the high-strength steel sheet preferably used as the base steel sheet may have any composition and structure as long as it has a desired tensile strength. Such high-strength steel sheet is, for example, a solid solution obtained by adding an interstitial solid solution element such as C and N and a substitutional solid solution element such as Si, Mn, P and Cr in order to improve various properties such as mechanical properties. Strengthening, precipitation strengthening by carbon/nitride such as Ti, Nb, V, Al, chemical compositional modification such as addition of strengthening elements such as W, Zr, Hf, Co, B, Cu, rare earth elements, recrystallization Toughening by recovery annealing at a temperature that does not occur or partial recrystallization strengthening that leaves an unrecrystallized region without completely recrystallizing, bainite or martensite single phase, or transformation structure such as ferrite and composite structure of these transformation structures Reinforcement by means of Hall-Petch equation where ferrite grain size is d: σ = σ 0 +kd -1/2 (where σ: stress, σ 0 , k: material constant) It is possible to use a high-strength steel sheet that has been subjected to structural or structural modifications such as strengthening and processing strengthening by rolling alone or in combination.
このような高強度鋼板の組成としては、例えば、Ｃ：０．１～０．４質量％、Ｓｉ：０～２．５質量％、Ｍｎ：１～３質量％、Ｐ：０～０．０５質量％、Ｓ：０～０．００５質量％、残部がＦｅおよび不可避的不純物からなる組成が挙げられる。さらに、前記組成にＣｕ、Ｔｉ、Ｖ、Ａｌ、Ｃｒなどの任意元素を１種または２種以上含有する組成が挙げられる。一般にこれらの任意元素は、合計で１０質量％程度を限度に添加されることが好ましい。
The composition of such a high-strength steel sheet is, for example, C: 0.1 to 0.4 mass%, Si: 0 to 2.5 mass%, Mn: 1 to 3 mass%, P: 0 to 0.05. %, S: 0 to 0.005% by mass, with the balance being Fe and inevitable impurities. Further, a composition containing one or more kinds of arbitrary elements such as Cu, Ti, V, Al and Cr in the above composition can be mentioned. Generally, it is preferable that these optional elements are added in a total amount of about 10% by mass.
また、前記高強度鋼板として商業的に入手可能なものとしては、例えば、ＪＦＥ－ＣＡ１１８０、ＪＦＥ－ＣＡ１３７０、ＪＦＥ－ＣＡ１４７０、ＪＦＥ－ＣＡ１１８０ＳＦ、ＪＦＥ－ＣＡ１１８０Ｙ１、ＪＦＥ－ＣＡ１１８０Ｙ２(以上、ＪＦＥスチール（株）製）、ＳＡＦＣ１１８０Ｄ（新日鐵住金（株）製）などが非限定的に例示できる。
Examples of commercially available high-strength steel sheets include JFE-CA1180, JFE-CA1370, JFE-CA1470, JFE-CA1180SF, JFE-CA1180Y1, JFE-CA1180Y2 (above, JFE Steel Corp.). Manufactured by Nippon Steel & Sumitomo Metal Co., Ltd. and the like can be exemplified without limitation.
また、前記高強度鋼板の板厚も特に限定されないが、一例として、前記高強度鋼板の板厚は、０．８ｍｍ以上が好ましく、１．２ｍｍ以上がより好ましい。また、一例として、前記高強度鋼板の板厚は、２．５ｍｍ以下が好ましく、２．０ｍｍ以下がより好ましい。
The plate thickness of the high-strength steel plate is not particularly limited, but as an example, the plate thickness of the high-strength steel plate is preferably 0.8 mm or more, more preferably 1.2 mm or more. Moreover, as an example, the plate thickness of the high-strength steel plate is preferably 2.5 mm or less, and more preferably 2.0 mm or less.
高強度鋼板（下地鋼板）を被覆する亜鉛めっきは、溶融めっき法、電気めっき法、無電解めっき法、蒸着めっき法などのいずれのめっき方法で形成されたものでもよい。工業的には溶融亜鉛めっき（溶融亜鉛めっき鋼板）、電気亜鉛めっき（電気亜鉛めっき鋼板）などが一般的である。本発明における亜鉛めっき鋼板には、上記めっき方法で形成された亜鉛めっき鋼板が含まれ、例えば、溶融亜鉛めっき鋼板、電気亜鉛めっき鋼板、無電解亜鉛めっき鋼板、蒸着亜鉛めっき鋼板が含まれる。また、本発明の亜鉛めっき鋼板には、前記溶融亜鉛めっき後に合金化処理して得られる合金化溶融亜鉛めっき鋼板が含まれる。
The zinc plating that coats the high-strength steel sheet (base steel sheet) may be formed by any plating method such as hot dipping, electroplating, electroless plating, and vapor deposition plating. Industrially, hot dip galvanization (hot dip galvanized steel sheet), electrogalvanization (electrogalvanized steel sheet), etc. are common. The galvanized steel sheet according to the present invention includes a galvanized steel sheet formed by the above plating method, and includes, for example, a hot-dip galvanized steel sheet, an electrogalvanized steel sheet, an electroless galvanized steel sheet, and a vapor-deposited galvanized steel sheet. Further, the galvanized steel sheet of the present invention includes an alloyed hot dip galvanized steel sheet obtained by an alloying treatment after the hot dip galvanizing.
本発明者らの研究および検討結果によれば、腐食過程における亜鉛めっきが被覆された鋼板内部への水素侵入は、湿潤下における腐食過程において、亜鉛めっきの犠牲防食作用により、地鉄上で多くの水素が発生することが大きく寄与していると考えられ、水素侵入を抑制するためには、腐食過程におけるＺｎの溶解を抑制することが重要であることが判明した。そして、亜鉛めっき表面に特定の金属塩を存在させることにより、その特定の金属塩がＺｎと錯体を形成することで鋼板表面に緻密な不働態皮膜が形成され、さらに、その特定の金属塩に含まれるイオンのｐＨ緩衝効果によりｐＨ８～１１に安定することでＺｎの溶解が抑制され、地鉄上での水素発生が抑えられ、それらの結果、鋼板内部への水素侵入を抑制できると考えられる。
According to the research and examination results of the present inventors, hydrogen penetration into the interior of the steel sheet coated with zinc plating in the corrosion process is more likely to occur on the base steel due to the sacrificial anticorrosive action of the zinc plating in the corrosion process under wet conditions. It is considered that the generation of hydrogen is greatly contributed, and it has been found that it is important to suppress dissolution of Zn in the corrosion process in order to suppress hydrogen invasion. Then, by allowing a specific metal salt to exist on the galvanized surface, the specific metal salt forms a complex with Zn to form a dense passivation film on the surface of the steel sheet, and further to the specific metal salt. It is believed that the pH buffering effect of the contained ions stabilizes the pH to 8 to 11 to suppress the dissolution of Zn, suppress the generation of hydrogen on the base iron, and consequently suppress the intrusion of hydrogen into the steel sheet. ..
このため本発明の高強度亜鉛めっき鋼板は、引張強度が１１８０ＭＰａ以上である亜鉛めっき鋼板の表面に、有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有する皮膜（x）を含む皮膜を形成する。この皮膜（x）は２種以上の金属塩（b）を含むものでもよい。
Therefore, the high-strength galvanized steel sheet of the present invention has a tensile strength of 1180 MPa or more on the surface of the galvanized steel sheet, organic resin (a), phosphoric acid group, phosphorous acid group, silicic acid group, molybdic acid group A film containing a film (x) containing a metal salt (b) containing at least one of them is formed. This film (x) may contain two or more kinds of metal salts (b).
本発明では、有機樹脂（a）により形成された樹脂皮膜中に金属塩（b）を含有させることで、金属塩（b）を鋼板表面に保持する形態を採るが、これは、樹脂皮膜が、腐食環境に晒されたときに鋼板表面を腐食環境から遮断するバリア層として機能するとともに、金属塩（b）を鋼板表面に強固に保持する機能を有するためである。
In the present invention, by incorporating the metal salt (b) in the resin film formed by the organic resin (a), the metal salt (b) is retained on the surface of the steel sheet. This is because it functions as a barrier layer that shields the surface of the steel sheet from the corrosive environment when exposed to the corrosive environment, and also has a function of firmly holding the metal salt (b) on the surface of the steel sheet.
有機樹脂（a）の種類に特に制限はなく、例えば、エポキシ樹脂、変性エポキシ樹脂、ウレタン樹脂、アルキド樹脂、アクリル樹脂、ポリエチレン樹脂、ポリブタジエン樹脂等のポリオレフィン樹脂、ポリエステル樹脂、アミノ樹脂、フェノール樹脂、フッ素樹脂、シリコン樹脂などが挙げられ、これらの１種以上を用いることができる。また、これらのなかで、ウレタン樹脂、エポキシ樹脂、アクリル樹脂、ポリエチレン樹脂が、腐食因子である水分や塩化物をバリアする効果が高いため特に好ましい。
The type of the organic resin (a) is not particularly limited, and examples thereof include epoxy resin, modified epoxy resin, urethane resin, alkyd resin, acrylic resin, polyethylene resin, polyolefin resin such as polybutadiene resin, polyester resin, amino resin, phenol resin, A fluororesin, a silicone resin, etc. are mentioned, and 1 or more types of these can be used. Further, among these, urethane resin, epoxy resin, acrylic resin, and polyethylene resin are particularly preferable because they have a high effect of blocking moisture and chloride, which are corrosion factors.
リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）は、Ｚｎ２＋とキレート錯体を形成し、安定した不働態皮膜を形成するものである。前記金属塩（b）としては、無機金属塩が挙げられる。前記金属塩（b）としては、アルカリ金属、アルカリ土類金属、アルミニウム、亜鉛、ジルコニウム等を含む金属塩が挙げられる。前記金属塩（b）としては、例えば、ポリリン酸ナトリウム（二リン酸ナトリウム）、トリポリリン酸ナトリウム、トリポリリン酸二水素アルミニウム、ポリリン酸亜鉛、トリポリリン酸亜鉛、リン酸カルシウム、リン酸マグネシウム亜鉛、亜リン酸亜鉛、亜リン酸カルシウム、亜リン酸亜鉛カルシウム、亜リン酸亜鉛マグネシウム、ケイ酸カルシウムジルコニウム、リン酸ジルコニウム、モリブデン酸亜鉛、モリブデン酸カルシウム、リンモリブデン酸アルミニウムなどが挙げられ、これらの１種以上を用いることができる。
The metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group, and a molybdic acid group forms a chelate complex with Zn 2+ and forms a stable passive film. is there. Examples of the metal salt (b) include inorganic metal salts. Examples of the metal salt (b) include metal salts containing alkali metals, alkaline earth metals, aluminum, zinc, zirconium and the like. Examples of the metal salt (b) include sodium polyphosphate (sodium diphosphate), sodium tripolyphosphate, aluminum dihydrogen tripolyphosphate, zinc polyphosphate, zinc tripolyphosphate, calcium phosphate, magnesium zinc phosphate, zinc phosphite. , Calcium phosphite, zinc calcium phosphite, zinc magnesium phosphite, calcium zirconium silicate, zirconium phosphate, zinc molybdate, calcium molybdate, aluminum phosphomolybdate, and the like, and use one or more of these. You can
また、これらのなかでも、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩は、ｐＨを高く保つ効果（ｐＨ緩衝効果）が得られるため、特に好ましい。アルカリ金属、アルカリ土類金属、アルミニウムは、イオン化傾向が高いため、他の金属塩に比べて、電離した際に水酸化物を作りにくい傾向がある。つまり、水酸化物イオン（ＯＨ－）の消費が他の金属イオンに比べ少ないため、ｐＨを高く（ＯＨ濃度を高く）保つと考えられる。このため金属塩（b）は、特にアルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩であることが好ましい。この場合も、皮膜（x）は２種以上の金属塩（b）を含むことができる。
Among these, a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum is particularly preferable because it has an effect of keeping pH high (pH buffering effect). Alkali metals, alkaline earth metals, and aluminum have a high ionization tendency, and thus tend to form a hydroxide when ionized, as compared with other metal salts. That is, since the hydroxide ion (OH − ) is consumed less than other metal ions, it is considered that the pH is kept high (the OH concentration is high). Therefore, the metal salt (b) is preferably a metal salt containing at least one selected from alkali metals, alkaline earth metals and aluminum. Also in this case, the film (x) can contain two or more kinds of metal salts (b).
金属塩（b）としては、コスト的に有利である点から、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩であることが好ましい。
The metal salt (b) is preferably a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group from the viewpoint of cost advantage.
腐食過程でのＺｎの溶解を抑制して遅れ破壊の発生を抑制する効果を発現するためには、皮膜（x）中の金属塩（b）の含有量（皮膜質量に対する割合）を５質量％以上とする必要がある。また、遅れ破壊を抑制するという観点からは金属塩（b）の含有量が多くなることに制限はないが、金属塩（b）の含有量が多すぎると、自動車などの用途において塗膜密着性が劣化するため、特に自動車などの用途の場合には、金属塩（b）の含有量は４４質量％以下とすることが好ましく、４０質量％以下とすることがより好ましい。
In order to suppress the dissolution of Zn in the corrosion process and to exert the effect of suppressing the occurrence of delayed fracture, the content of metal salt (b) in the film (x) (ratio to the film mass) is 5% by mass. It is necessary to be above. In addition, from the viewpoint of suppressing delayed fracture, there is no limitation to increase the content of the metal salt (b), but if the content of the metal salt (b) is too high, the coating film adheres in applications such as automobiles. In particular, for applications such as automobiles, the content of the metal salt (b) is preferably 44% by mass or less, and more preferably 40% by mass or less because the property deteriorates.
また、鋼板片面あたりの金属塩（b）の付着量が少ないと、遅れ破壊の発生を抑制する効果が十分に得られないおそれがあり、このため金属塩（b）の付着量は鋼板片面あたり５０ｍｇ／ｍ２以上とすることが好ましい。
If the amount of the metal salt (b) deposited on one side of the steel sheet is small, the effect of suppressing the occurrence of delayed fracture may not be sufficiently obtained. Therefore, the amount of the metal salt (b) deposited on one side of the steel sheet It is preferably 50 mg/m 2 or more.
皮膜（x）の膜厚については、皮膜（x）が薄過ぎると鋼板を腐食環境から遮断するバリア層としての機能を発揮できなくなるため、皮膜（x）の膜厚は０．３μｍ以上とする。一方、自動車などの用途では、鋼板はプレス加工により所定の形状に加工された後に、スポット溶接により鋼板どうしを組み付ける工程がある。このとき、皮膜（x）が厚過ぎると溶接時の電流が流れず溶接不良となる場合があるため、スポット溶接を鋼板の接合に用いる場合は、皮膜（x）の膜厚は４．０μｍ以下であることが好ましい。
Regarding the film thickness of the film (x), if the film (x) is too thin, it cannot function as a barrier layer that shields the steel sheet from the corrosive environment, so the film thickness of the film (x) is 0.3 μm or more. .. On the other hand, in applications such as automobiles, there is a step of assembling steel sheets by spot welding after the steel sheets are processed into a predetermined shape by press working. At this time, if the coating (x) is too thick, the welding current may not flow and welding failure may occur. Therefore, when spot welding is used for joining steel sheets, the thickness of the coating (x) is 4.0 μm or less. Is preferred.
また、耐遅れ破壊性がさらに高められる点から、金属塩（b）がトリポリリン酸二水素アルミニウムであり、皮膜（x）の膜厚が１．０μｍ以上であり、皮膜（x）中でのトリポリリン酸二水素アルミニウムの含有量が１７～４５質量％である態様が好ましい。
Further, since the delayed fracture resistance is further enhanced, the metal salt (b) is aluminum dihydrogen tripolyphosphate, and the film thickness of the film (x) is 1.0 μm or more. An embodiment in which the content of aluminum dihydrogen acid is 17 to 45 mass% is preferable.
本発明において亜鉛めっき鋼板上に形成される皮膜（x）は、上述したように有機樹脂（a）と特定の金属塩（b）を含む。この際、前記金属塩（b）は、前記皮膜（x）中に溶解された状態で含まれてもよいし、粒子の形態で含まれてもよい。また、前記金属塩（b）が皮膜（x）中に粒子の形態で含まれる場合、その粒子径（最大粒子径）は、特に制限されない。
The film (x) formed on the galvanized steel sheet in the present invention contains the organic resin (a) and the specific metal salt (b) as described above. At this time, the metal salt (b) may be contained in the film (x) in a dissolved state or in the form of particles. When the metal salt (b) is contained in the film (x) in the form of particles, the particle size (maximum particle size) is not particularly limited.
ただし、本発明では、皮膜（x）は、金属塩（b）以外には、最大粒子径が該皮膜（x）の膜厚以上である粒子成分を含有しないことが必要である。従来の樹脂被覆鋼板では、例えば、皮膜の導電性を向上させて溶接性を改善する目的で、皮膜中に導電性粒子を添加する場合がある。また、その他にも、プレス加工性を改善するために固体潤滑剤を添加するなど、種々の目的で粒子成分を添加する場合がある。
However, in the present invention, it is necessary that the film (x) does not contain, other than the metal salt (b), a particle component having a maximum particle diameter equal to or larger than the film thickness of the film (x). In a conventional resin-coated steel sheet, for example, conductive particles may be added to the coating for the purpose of improving the conductivity of the coating and improving the weldability. In addition to these, particle components may be added for various purposes such as addition of a solid lubricant in order to improve press workability.
しかし、本発明の高強度亜鉛めっき鋼板の場合、皮膜（x）中に金属塩（b）以外の粒子成分を添加すると、粒子と皮膜（有機樹脂）の界面が腐食の起点となり、本発明の効果（耐遅れ破壊性の向上）の妨げとなりやすい。特に、粒子成分の粒径が皮膜（x）の膜厚に比べて大きいと欠陥が生じやすく、腐食の起点となる懸念がある。このため皮膜（x）には、金属塩（b）以外には、最大粒子径が皮膜（x）の膜厚以上である粒子成分を含有させない。このような粒子成分としては、導電性粒子、固体潤滑剤粒子が挙げられる。導電性粒子としては、セラミックス粒子、鉄合金粒子、ステンレス粒子等が挙げられる。固体潤滑剤粒子としては、二硫化モリブデン、グラファイト、窒化ホウ素等の無機固体潤滑剤粒子が挙げられる。
However, in the case of the high-strength galvanized steel sheet of the present invention, when a particle component other than the metal salt (b) is added to the film (x), the interface between the particles and the film (organic resin) becomes a starting point of corrosion, It tends to hinder the effect (improvement of delayed fracture resistance). In particular, if the particle size of the particle component is larger than the film thickness of the film (x), defects are likely to occur and there is a concern that it may be the starting point of corrosion. Therefore, the coating (x) does not contain any particle component other than the metal salt (b) whose maximum particle diameter is equal to or larger than the thickness of the coating (x). Examples of such a particle component include conductive particles and solid lubricant particles. Examples of the conductive particles include ceramic particles, iron alloy particles, stainless particles and the like. Examples of the solid lubricant particles include inorganic solid lubricant particles such as molybdenum disulfide, graphite and boron nitride.
なお、皮膜（x）の膜厚の下限は０．３μｍであるので、含有が許容される粒子成分の最大粒子径を０．３μｍ未満、好ましくは０．２μｍ以下とすれば、皮膜（x）の膜厚に拘わりなく、その条件を満たすことになる。
ここで、粒子成分の最大粒子径とは、皮膜（x）を、トルエンやアセトン等の前記皮膜（x）を溶解可能な有機溶媒により溶解させたのち、粒子成分を、ポリテトラフルオロエチレン等のフィルターで捕集し、洗浄、電解質溶媒に分散させたのちにコールター法により体積球相当径を測定して得られる粒度分布の最大値である。なお、皮膜（x）に複数種類の粒子成分が含まれる場合には、上記捕集後の粒子成分を電解質溶媒に分散させたのちに遠心分離法で粒子成分ごとに分離してから、それぞれの粒子成分についてコールター法により体積球相当径を測定すればよい。また、前記粒子成分が市販品として入手可能である場合、前記粒子成分の最大粒子径のカタログ値を、前記粒子成分の最大粒子径として用いてもよい。また、ここでいう最大粒子径とは一次粒子の最大粒子径を意味する。 Since the lower limit of the film thickness of the film (x) is 0.3 μm, if the maximum particle size of the particle component allowed to be contained is less than 0.3 μm, preferably 0.2 μm or less, the film (x) The condition is satisfied regardless of the film thickness of.
Here, the maximum particle diameter of the particle component means that the film (x) is dissolved in an organic solvent capable of dissolving the film (x) such as toluene or acetone, and then the particle component is changed to polytetrafluoroethylene or the like. It is the maximum value of the particle size distribution obtained by collecting with a filter, washing and dispersing in an electrolyte solvent, and then measuring the volume sphere equivalent diameter by the Coulter method. When the film (x) contains a plurality of types of particle components, the collected particle components are dispersed in an electrolyte solvent and then separated by a centrifugal method to separate each of the particle components. The volume sphere equivalent diameter of the particle component may be measured by the Coulter method. Further, when the particle component is commercially available, the catalog value of the maximum particle size of the particle component may be used as the maximum particle size of the particle component. The maximum particle size referred to here means the maximum particle size of the primary particles.
ここで、粒子成分の最大粒子径とは、皮膜（x）を、トルエンやアセトン等の前記皮膜（x）を溶解可能な有機溶媒により溶解させたのち、粒子成分を、ポリテトラフルオロエチレン等のフィルターで捕集し、洗浄、電解質溶媒に分散させたのちにコールター法により体積球相当径を測定して得られる粒度分布の最大値である。なお、皮膜（x）に複数種類の粒子成分が含まれる場合には、上記捕集後の粒子成分を電解質溶媒に分散させたのちに遠心分離法で粒子成分ごとに分離してから、それぞれの粒子成分についてコールター法により体積球相当径を測定すればよい。また、前記粒子成分が市販品として入手可能である場合、前記粒子成分の最大粒子径のカタログ値を、前記粒子成分の最大粒子径として用いてもよい。また、ここでいう最大粒子径とは一次粒子の最大粒子径を意味する。 Since the lower limit of the film thickness of the film (x) is 0.3 μm, if the maximum particle size of the particle component allowed to be contained is less than 0.3 μm, preferably 0.2 μm or less, the film (x) The condition is satisfied regardless of the film thickness of.
Here, the maximum particle diameter of the particle component means that the film (x) is dissolved in an organic solvent capable of dissolving the film (x) such as toluene or acetone, and then the particle component is changed to polytetrafluoroethylene or the like. It is the maximum value of the particle size distribution obtained by collecting with a filter, washing and dispersing in an electrolyte solvent, and then measuring the volume sphere equivalent diameter by the Coulter method. When the film (x) contains a plurality of types of particle components, the collected particle components are dispersed in an electrolyte solvent and then separated by a centrifugal method to separate each of the particle components. The volume sphere equivalent diameter of the particle component may be measured by the Coulter method. Further, when the particle component is commercially available, the catalog value of the maximum particle size of the particle component may be used as the maximum particle size of the particle component. The maximum particle size referred to here means the maximum particle size of the primary particles.
本発明の皮膜（x）は、有機樹脂（a）と特定の金属塩（b）を含有し、且つ金属塩（b）以外には、上述したような粒径の大きい粒子成分を含有しないため、金属塩（b）以外に皮膜中に塗膜欠陥として作用する粒子が存在せず、粒子近傍が腐食起点となることもなく、耐遅れ破壊性を担保することができる。
Since the film (x) of the present invention contains the organic resin (a) and the specific metal salt (b), and does not contain the above-mentioned large particle component other than the metal salt (b). In addition to the metal salt (b), there are no particles that act as coating film defects in the film, and the vicinity of the particles does not become the starting point of corrosion, and delayed fracture resistance can be secured.
また、以上のような観点からは、皮膜（x）は、導電性粒子および固体潤滑剤粒子を含まないことが好ましく、皮膜（x）は、金属塩（b）以外の粒子成分を含まないことがより好ましく、また、皮膜（x）は、有機樹脂（a）と金属塩（b）のみからなることがさらに好ましいと言える。
From the above viewpoint, it is preferable that the film (x) does not contain conductive particles and solid lubricant particles, and the film (x) does not contain particle components other than the metal salt (b). It can be said that the film (x) is more preferably composed of only the organic resin (a) and the metal salt (b).
本発明の高強度亜鉛めっき鋼板は、皮膜（x）を鋼板片面に形成したもの、鋼板両面に形成したもの、のいずれでもよい。
The high-strength galvanized steel sheet according to the present invention may have the coating (x) formed on one side of the steel sheet or both sides of the steel sheet.
皮膜（x）中の金属塩（b）の含有量や鋼板片面あたりの付着量を測定する方法としては、例えば、蛍光Ｘ線分析が挙げられる。具体的には、皮膜表面にＸ線を照射し、金属塩（b）に含まれる金属元素の蛍光Ｘ線の強度を測定し、検量線と比較することで算出することができる。
As a method for measuring the content of the metal salt (b) in the film (x) and the amount attached on one side of the steel sheet, there is fluorescent X-ray analysis, for example. Specifically, it can be calculated by irradiating the film surface with X-rays, measuring the intensity of fluorescent X-rays of the metal element contained in the metal salt (b), and comparing with the calibration curve.
また、皮膜（x）の膜厚については、皮膜断面を観察し、任意視野の複数箇所（例えば、３箇所）で皮膜（x）の厚さ（基材の亜鉛めっき鋼板面から皮膜（x）の表面までの厚さ）を測定し、それらの平均値を膜厚とする。断面加工の方法としては特に限定されないが、例えばＦＩＢ（Focused Ion Beam）加工などが挙げられる。
Regarding the film thickness of the film (x), the cross section of the film is observed, and the thickness of the film (x) (from the galvanized steel plate surface of the substrate to the film (x) Thickness up to the surface of) is measured, and the average value thereof is taken as the film thickness. The cross-section processing method is not particularly limited, and examples thereof include FIB (Focused Ion Beam) processing.
次に、以上述べた本発明の実施形態にかかる高強度亜鉛めっき鋼板の製造方法について説明する。
この製造方法では、上述したような引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む）の表面に、有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ金属塩（b）以外には、最大粒子径が形成すべき皮膜（x）の膜厚以上である粒子成分を含有しない表面処理液（樹脂皮膜形成用表面処理液）を付着させることにより、前記亜鉛めっき鋼板の表面に上述の皮膜（x）を形成する。 Next, a method for manufacturing the high-strength galvanized steel sheet according to the embodiment of the present invention described above will be described.
In this manufacturing method, the organic resin (a), a phosphoric acid group, a phosphorous acid group, on the surface of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including a galvannealed steel sheet) as described above, Contains a metal salt (b) containing at least one of a silicic acid group and a molybdic acid group, and has a maximum particle size of at least the film thickness of the film (x) to be formed, other than the metal salt (b). The above-mentioned coating (x) is formed on the surface of the galvanized steel sheet by adhering a surface treatment liquid (surface treatment liquid for resin film formation) that does not contain a certain particle component.
この製造方法では、上述したような引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む）の表面に、有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ金属塩（b）以外には、最大粒子径が形成すべき皮膜（x）の膜厚以上である粒子成分を含有しない表面処理液（樹脂皮膜形成用表面処理液）を付着させることにより、前記亜鉛めっき鋼板の表面に上述の皮膜（x）を形成する。 Next, a method for manufacturing the high-strength galvanized steel sheet according to the embodiment of the present invention described above will be described.
In this manufacturing method, the organic resin (a), a phosphoric acid group, a phosphorous acid group, on the surface of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including a galvannealed steel sheet) as described above, Contains a metal salt (b) containing at least one of a silicic acid group and a molybdic acid group, and has a maximum particle size of at least the film thickness of the film (x) to be formed, other than the metal salt (b). The above-mentioned coating (x) is formed on the surface of the galvanized steel sheet by adhering a surface treatment liquid (surface treatment liquid for resin film formation) that does not contain a certain particle component.
なお、この製造方法において、前記表面処理液に金属塩（b）以外の粒子成分を含有させる場合、形成すべき皮膜（x）の膜厚の下限を予め設定し、その膜厚に応じた最大粒子径の粒子成分を表面処理液に含有させればよい。ここで、形成される皮膜（x）の膜厚の下限は０．３μｍであるので、表面処理液中に含有させる粒子成分の最大粒子径を０．３μｍ未満、好ましくは０．２μｍ以下とすれば、皮膜（x）の膜厚に拘わりなく、上記の条件を満たすことになる。
In this production method, when the surface treatment liquid contains a particle component other than the metal salt (b), the lower limit of the film thickness of the film (x) to be formed is set in advance and the maximum value corresponding to the film thickness is set. It suffices if the surface treatment liquid contains a particle component having a particle size. Here, since the lower limit of the film thickness of the formed film (x) is 0.3 μm, the maximum particle diameter of the particle component contained in the surface treatment liquid is less than 0.3 μm, preferably 0.2 μm or less. For example, the above conditions are satisfied regardless of the film thickness of the film (x).
この製造方法において、表面処理液が含有する有機樹脂（a）及び金属塩（b）の詳細、表面処理液が、金属塩（b）以外には所定粒径以上の粒子成分を含有しない理由、形成される皮膜（x）の膜厚や金属塩（b）の含有量の限定理由などは、さきに説明した高強度亜鉛めっき鋼板に関する理由と同様である。
In this manufacturing method, the details of the organic resin (a) and the metal salt (b) contained in the surface treatment liquid, the reason why the surface treatment liquid does not contain a particle component having a predetermined particle size or more other than the metal salt (b), The reasons for limiting the film thickness of the formed film (x) and the content of the metal salt (b) are the same as those for the high-strength galvanized steel sheet described above.
また、この製造方法における好ましい条件は以下の通りであり、その理由も、さきに説明した高強度亜鉛めっき鋼板に関する理由と同様である。
（ｉ）金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩であること。
（ii）金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩であること。
（iii）皮膜（x）中での鋼板片面あたりの金属塩（b）の付着量が５０ｍｇ／ｍ２以上であること。
（iv）金属塩（b）がトリポリリン酸二水素アルミニウムであり、皮膜（x）の膜厚が１．０μｍ以上であり、皮膜（x）中でのトリポリリン酸二水素アルミニウムの含有量が１７～４５質量％であること。
（v）表面処理液は、導電性粒子および固体潤滑剤粒子を含有しないこと。好ましくは、表面処理液は金属塩（b）以外の粒子成分を含有しないこと。特に好ましくは、表面処理液は、溶媒中に有機樹脂（a）と金属塩（b）のみを含有すること。
（vi）皮膜（x）中での金属塩（b）の含有量が４４質量％以下であること、好ましくは４０質量％以下であること。
（vii）皮膜（x）の膜厚が４．０μｍ以下であること。 The preferable conditions in this manufacturing method are as follows, and the reason is the same as the reason for the high-strength galvanized steel sheet described above.
(I) The metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum.
(Ii) The metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group.
(Iii) The amount of the metal salt (b) deposited on one surface of the steel sheet in the film (x) is 50 mg/m 2 or more.
(Iv) The metal salt (b) is aluminum dihydrogen tripolyphosphate, the film thickness of the film (x) is 1.0 μm or more, and the content of aluminum dihydrogen tripolyphosphate in the film (x) is 17 to Must be 45% by mass.
(V) The surface treatment liquid should not contain conductive particles or solid lubricant particles. Preferably, the surface treatment liquid contains no particle component other than the metal salt (b). Particularly preferably, the surface treatment liquid contains only the organic resin (a) and the metal salt (b) in the solvent.
(Vi) The content of the metal salt (b) in the film (x) is 44 mass% or less, preferably 40 mass% or less.
(Vii) The film thickness of the film (x) is 4.0 μm or less.
（ｉ）金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩であること。
（ii）金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩であること。
（iii）皮膜（x）中での鋼板片面あたりの金属塩（b）の付着量が５０ｍｇ／ｍ２以上であること。
（iv）金属塩（b）がトリポリリン酸二水素アルミニウムであり、皮膜（x）の膜厚が１．０μｍ以上であり、皮膜（x）中でのトリポリリン酸二水素アルミニウムの含有量が１７～４５質量％であること。
（v）表面処理液は、導電性粒子および固体潤滑剤粒子を含有しないこと。好ましくは、表面処理液は金属塩（b）以外の粒子成分を含有しないこと。特に好ましくは、表面処理液は、溶媒中に有機樹脂（a）と金属塩（b）のみを含有すること。
（vi）皮膜（x）中での金属塩（b）の含有量が４４質量％以下であること、好ましくは４０質量％以下であること。
（vii）皮膜（x）の膜厚が４．０μｍ以下であること。 The preferable conditions in this manufacturing method are as follows, and the reason is the same as the reason for the high-strength galvanized steel sheet described above.
(I) The metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum.
(Ii) The metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group.
(Iii) The amount of the metal salt (b) deposited on one surface of the steel sheet in the film (x) is 50 mg/m 2 or more.
(Iv) The metal salt (b) is aluminum dihydrogen tripolyphosphate, the film thickness of the film (x) is 1.0 μm or more, and the content of aluminum dihydrogen tripolyphosphate in the film (x) is 17 to Must be 45% by mass.
(V) The surface treatment liquid should not contain conductive particles or solid lubricant particles. Preferably, the surface treatment liquid contains no particle component other than the metal salt (b). Particularly preferably, the surface treatment liquid contains only the organic resin (a) and the metal salt (b) in the solvent.
(Vi) The content of the metal salt (b) in the film (x) is 44 mass% or less, preferably 40 mass% or less.
(Vii) The film thickness of the film (x) is 4.0 μm or less.
亜鉛めっき鋼板表面に皮膜（x）を形成するには、有機樹脂（a）を溶媒（水および／または有機溶剤）に溶解および／または分散させ、これに金属塩（b）（さらに必要に応じて他の成分）を添加した表面処理液を亜鉛めっき鋼板表面に付着させてコーティングした後、乾燥（一般に加熱乾燥）させる方法が採られる。
In order to form the film (x) on the surface of the galvanized steel sheet, the organic resin (a) is dissolved and/or dispersed in a solvent (water and/or organic solvent), and the metal salt (b) (and, if necessary, And other components) are added to the surface of the galvanized steel sheet to coat the surface of the galvanized steel sheet, followed by drying (generally heat drying).
表面処理液を亜鉛めっき鋼板表面に付着させてコーティングする方法に特別な制限はなく、公知の方法、例えば、塗布方式、浸漬方式、スプレー方式などのいずれかを適用できる。塗布方式では、バーコーター、ロールコーター（３ロール方式、２ロール方式など）、スクイズコーター、ダイコーターなどのいずれの塗布手段を用いてもよい。また、スクイズコーターなどによる塗布処理、浸漬処理、スプレー処理の後に、エアナイフ法やロール絞り法により塗布量の調整、外観の均一化、膜厚の均一化を行うことも可能である。
There is no particular limitation on the method for coating the surface of the galvanized steel sheet by applying the surface treatment liquid, and any known method such as a coating method, a dipping method, or a spray method can be applied. In the coating method, any coating means such as a bar coater, a roll coater (3 roll system, 2 roll system, etc.), a squeeze coater, a die coater, etc. may be used. It is also possible to adjust the coating amount, make the appearance uniform, and make the film thickness uniform by an air knife method or a roll squeezing method after the coating treatment using a squeeze coater, the dipping treatment, and the spray treatment.
亜鉛めっき鋼板表面に付着させコーティングした表面処理液を加熱乾燥する方法は任意であり、例えば、ドライヤー、熱風炉、高周波誘導加熱炉、赤外線炉等の手段を用いることができる。
The method of heating and drying the surface treatment liquid that is attached to the surface of the galvanized steel sheet and coated is arbitrary, and for example, a dryer, a hot-air stove, a high-frequency induction heating furnace, an infrared furnace, or the like can be used.
上記の方法で亜鉛めっき鋼板表面に皮膜（x）を形成する際に、皮膜（x）中での金属塩（b）の含有量は、有機樹脂（a）と金属塩（b）の配合比率を変えることにより調整することができる。また、鋼板片面あたり金属塩（b）の付着量や皮膜（x）の膜厚は、表面処理液の濃度や付着量（コーティング量）を変えることにより調整することができる。
When the coating (x) is formed on the surface of the galvanized steel sheet by the above method, the content of the metal salt (b) in the coating (x) is the mixing ratio of the organic resin (a) and the metal salt (b). It can be adjusted by changing. Further, the amount of the metal salt (b) attached and the film thickness of the film (x) per one side of the steel sheet can be adjusted by changing the concentration of the surface treatment liquid and the amount of the attached (coating amount).
本発明においてめっき下地鋼板として使用される高強度鋼板の製造方法は特に限定されない。本発明の理解を容易にするために、製鋼からの一連のプロセスについて、一例を挙げて簡単に説明する。但し、めっき下地鋼板となる高強度鋼板の製造工程としては、以下の例示に限定されるものではない。
The method for producing the high-strength steel sheet used as the plating base steel sheet in the present invention is not particularly limited. In order to facilitate understanding of the present invention, a series of processes from steelmaking will be briefly described with an example. However, the manufacturing process of the high-strength steel plate to be the plated base steel plate is not limited to the following examples.
所定の成分組成の鋼を溶製し、常法に従い連続鋳造でスラブとする。次いで、得られたスラブを加熱炉中で１１００～１３００℃の温度で加熱し、７５０～９５０℃の仕上げ温度で熱間圧延を行い、５００～６５０℃にて巻き取る。これに続いて酸洗後、圧下率３０～７０％の冷間圧延を行う。その後、必要に応じて、常法に従い、アルカリまたはアルカリと界面活性剤および鋼板に吸着して分子膜を形成する窒素や硫黄を含む有機化合物との混合溶液による洗浄、電解洗浄、温水洗浄、乾燥を行う清浄化処理を行った後、６５０～９００℃にて加熱処理し、急速冷却を行い、鋼板の引張強度の調整を行う。さらに必要に応じて、常法に従い０．０１～０．５％程度の調質圧延を行うことで所望の引張強度を有する鋼板を得る。
∙ Melt steel with the prescribed composition and make it into a slab by continuous casting according to the usual method. Next, the obtained slab is heated in a heating furnace at a temperature of 1100 to 1300° C., hot-rolled at a finishing temperature of 750 to 950° C., and wound at 500 to 650° C. Following this, after pickling, cold rolling with a reduction rate of 30 to 70% is performed. Then, if necessary, according to a conventional method, washing with an alkali or a mixed solution of an alkali and an organic compound containing nitrogen and sulfur that adsorbs a surfactant and a steel sheet to form a molecular film, electrolytic washing, hot water washing, and drying After performing a cleaning treatment to perform, heat treatment is performed at 650 to 900° C., rapid cooling is performed, and the tensile strength of the steel sheet is adjusted. Further, if necessary, temper rolling of about 0.01 to 0.5% is performed according to a conventional method to obtain a steel sheet having a desired tensile strength.
本発明の表面処理液は、引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む。）の遅れ破壊を抑制するための皮膜（x）を含む皮膜を前記亜鉛めっき鋼板の表面に形成するためのものであり、有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ金属塩（b）以外には最大粒子径が形成すべき皮膜（x）の膜厚以上である粒子成分を含有せず、全固形分中での金属塩（b）の含有割合が５質量％以上である。なお、この表面処理液では、金属塩（b）以外の粒子成分を含有させる場合、当該表面処理液を適用して形成すべき皮膜（x）の膜厚の下限を予め設定し、その膜厚に応じた最大粒子径の粒子成分を含有させればよい。
The surface treatment liquid of the present invention comprises a galvanized steel sheet having a coating (x) for suppressing delayed fracture of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including galvannealed steel sheet). The organic resin (a) and a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group and a molybdic acid group, And, other than the metal salt (b), it does not contain a particle component having a maximum particle size equal to or larger than the film thickness of the film (x) to be formed, and the content ratio of the metal salt (b) in the total solid content is 5 It is at least mass%. In this surface treatment liquid, when a particle component other than the metal salt (b) is contained, the lower limit of the film thickness of the film (x) to be formed by applying the surface treatment liquid is set in advance, and the film thickness It suffices to include a particle component having a maximum particle diameter corresponding to the above.
この表面処理液で亜鉛めっき鋼板表面に形成される皮膜によって腐食過程での遅れ破壊の発生を抑制する効果を発現するためには、表面処理液の全固形分中での金属塩（b）の含有割合（表面処理液中の全固形分の含有質量に対する前記金属塩（b）の含有質量の割合）を５質量％以上とする必要がある。また、遅れ破壊を抑制するという観点からは金属塩（b）の含有割合が多くなることに制限はないが、金属塩（b）の含有割合が多すぎると、自動車などの用途において塗膜密着性および塗装後耐食性が劣化するため、特に自動車などの用途の場合には、表面処理液の全固形分中での金属塩（b）の含有割合は４４質量％以下とすることが好ましく、４０質量％以下とすることがより好ましい。
In order to exert the effect of suppressing the occurrence of delayed fracture in the corrosion process by the film formed on the surface of the galvanized steel sheet with this surface treatment solution, the metal salt (b) in the total solid content of the surface treatment solution The content ratio (the ratio of the content mass of the metal salt (b) to the content mass of the total solid content in the surface treatment liquid) needs to be 5 mass% or more. In addition, from the viewpoint of suppressing delayed fracture, there is no limit to increasing the content of the metal salt (b), but if the content of the metal salt (b) is too high, it will adhere to the coating film in applications such as automobiles. In particular, in the case of applications such as automobiles, the content of the metal salt (b) in the total solid content of the surface treatment liquid is preferably 44% by mass or less, since the corrosion resistance and the corrosion resistance after coating deteriorate. It is more preferable that the content is not more than mass %.
また、この表面処理液において、含有する有機樹脂（a）および金属塩（b）と溶媒の詳細、金属塩（b）以外には所定粒径以上の粒子成分を含有しない理由などは、さきに説明した高強度亜鉛めっき鋼板及びその製造方法に関するものと同様である。
In addition, the details of the organic resin (a) and the metal salt (b) and the solvent contained in this surface treatment liquid, the reason why no particle component having a predetermined particle size or more other than the metal salt (b) is mentioned before. This is the same as that of the high-strength galvanized steel sheet and the manufacturing method thereof described above.
また、この表面処理液における好ましい条件は以下の通りであり、その理由も、さきに説明した高強度亜鉛めっき鋼板に関する理由と同様である。
（ｉ）金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩であること。
（ii）金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩であること。
（iii）金属塩（b）がトリポリリン酸二水素アルミニウムであること。
（iv）導電性粒子および固体潤滑剤粒子を含有しないこと。好ましくは、金属塩（b）以外の粒子成分を含有しないこと。特に好ましくは、溶媒中に有機樹脂（a）と金属塩（b）のみを含有すること。 The preferable conditions for this surface treatment solution are as follows, and the reason is the same as the reason for the high-strength galvanized steel sheet described above.
(I) The metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum.
(Ii) The metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group.
(Iii) The metal salt (b) is aluminum dihydrogen tripolyphosphate.
(Iv) Conductive particles and solid lubricant particles are not included. Preferably, it does not contain a particle component other than the metal salt (b). Particularly preferably, the solvent contains only the organic resin (a) and the metal salt (b).
（ｉ）金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩であること。
（ii）金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩であること。
（iii）金属塩（b）がトリポリリン酸二水素アルミニウムであること。
（iv）導電性粒子および固体潤滑剤粒子を含有しないこと。好ましくは、金属塩（b）以外の粒子成分を含有しないこと。特に好ましくは、溶媒中に有機樹脂（a）と金属塩（b）のみを含有すること。 The preferable conditions for this surface treatment solution are as follows, and the reason is the same as the reason for the high-strength galvanized steel sheet described above.
(I) The metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum.
(Ii) The metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group and a silicic acid group.
(Iii) The metal salt (b) is aluminum dihydrogen tripolyphosphate.
(Iv) Conductive particles and solid lubricant particles are not included. Preferably, it does not contain a particle component other than the metal salt (b). Particularly preferably, the solvent contains only the organic resin (a) and the metal salt (b).
以上のようにして、引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む。）の表面に皮膜（x）を含む皮膜を有する１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板を製造できる。かかる高強度亜鉛めっき鋼板は、耐遅れ破壊性に優れる。さらに、良好な塗装後耐食性を有する。
As described above, high-strength zinc having a tensile strength of 1180 MPa or more, which has a coating containing the coating (x) on the surface of a galvanized steel sheet having a tensile strength of 1180 MPa or more (however, including galvannealed steel sheet). Can manufacture plated steel sheets. Such a high-strength galvanized steel sheet has excellent delayed fracture resistance. Furthermore, it has good corrosion resistance after painting.
＜第二実施形態＞
次に、本発明の第二実施形態にかかる高強度亜鉛めっき鋼板について説明する。本発明の第二実施形態にかかる高強度亜鉛めっき鋼板は、鋼板表面に、無機皮膜と、上述の皮膜（x）を含む皮膜を有する。具体的には、前記高強度亜鉛めっき鋼板は、引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（合金化溶融亜鉛めっき鋼板を含む。）の表面に、所定の無機皮膜を有し、さらにその上に上述の皮膜（x）を有する。なお、本実施形態において、無機皮膜以外の構成については、上述した第一実施形態と同様であるので、その詳細な説明は省略する。 <Second embodiment>
Next, a high strength galvanized steel sheet according to the second embodiment of the present invention will be described. The high-strength galvanized steel sheet according to the second embodiment of the present invention has an inorganic coating and a coating including the coating (x) on the surface of the steel. Specifically, the high-strength galvanized steel sheet has a predetermined inorganic coating on the surface of a galvanized steel sheet (including an alloyed hot-dip galvanized steel sheet) having a tensile strength of 1180 MPa or more, and further has the above-mentioned structure thereon. It has a film (x). In this embodiment, the configuration other than the inorganic film is the same as that of the above-described first embodiment, and thus detailed description thereof will be omitted.
次に、本発明の第二実施形態にかかる高強度亜鉛めっき鋼板について説明する。本発明の第二実施形態にかかる高強度亜鉛めっき鋼板は、鋼板表面に、無機皮膜と、上述の皮膜（x）を含む皮膜を有する。具体的には、前記高強度亜鉛めっき鋼板は、引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（合金化溶融亜鉛めっき鋼板を含む。）の表面に、所定の無機皮膜を有し、さらにその上に上述の皮膜（x）を有する。なお、本実施形態において、無機皮膜以外の構成については、上述した第一実施形態と同様であるので、その詳細な説明は省略する。 <Second embodiment>
Next, a high strength galvanized steel sheet according to the second embodiment of the present invention will be described. The high-strength galvanized steel sheet according to the second embodiment of the present invention has an inorganic coating and a coating including the coating (x) on the surface of the steel. Specifically, the high-strength galvanized steel sheet has a predetermined inorganic coating on the surface of a galvanized steel sheet (including an alloyed hot-dip galvanized steel sheet) having a tensile strength of 1180 MPa or more, and further has the above-mentioned structure thereon. It has a film (x). In this embodiment, the configuration other than the inorganic film is the same as that of the above-described first embodiment, and thus detailed description thereof will be omitted.
本実施形態において、亜鉛めっき鋼板表面に形成される無機皮膜は、シラン化合物、ジルコニウム化合物から選ばれる少なくとも１種（（c）成分）を含有する。（c）成分としては、特に限定されないが、シラン化合物としては、官能基を有するシラン化合物、例えば、ビニル基、エポキシ基、メタクリル基、アクリル基、アミノ基、メルカプト基、イソシアネート基などを有するシラン化合物が挙げられる。また、ジルコニウム化合物としては、塩化ジルコニウム、塩化ジルコニル、硫酸ジルコニウム、硫酸ジルコニル、硝酸ジルコニウム、硝酸ジルコニル、ジルコニウムフッ化水素酸、臭化ジルコニル、酢酸ジルコニル、炭酸ジルコニル、炭酸ジルコニウムアンモニウムなどが挙げられる。
In the present embodiment, the inorganic coating formed on the surface of the galvanized steel sheet contains at least one type ((c) component) selected from silane compounds and zirconium compounds. The component (c) is not particularly limited, but as the silane compound, a silane compound having a functional group, for example, a silane having a vinyl group, an epoxy group, a methacryl group, an acryl group, an amino group, a mercapto group, an isocyanate group, or the like. Compounds. Examples of zirconium compounds include zirconium chloride, zirconyl chloride, zirconium sulfate, zirconyl sulfate, zirconium nitrate, zirconyl nitrate, zirconium hydrofluoric acid, zirconyl bromide, zirconyl acetate, zirconyl carbonate, and ammonium zirconium carbonate.
前記（c）成分の鋼板片面あたりの付着量は２００～５００ｍｇ／ｍ２が好ましい。鋼板片面あたりの（c）成分の付着量が前記範囲であると、塗膜密着性をより高めやすくなる。
The amount of the component (c) deposited on one surface of the steel sheet is preferably 200 to 500 mg/m 2 . When the amount of the component (c) attached to one surface of the steel sheet is within the above range, the coating film adhesion can be more easily enhanced.
前記（c）成分の鋼板片面あたりの付着量を測定する方法は、例えば、蛍光Ｘ線分析が挙げられる。具体的には、皮膜表面にＸ線を照射し、（c）成分に含まれる金属元素の蛍光Ｘ線の強度を測定し、検量線と比較することで算出することができる。
Fluorescent X-ray analysis is an example of a method for measuring the amount of the component (c) deposited on one side of the steel sheet. Specifically, it can be calculated by irradiating the surface of the film with X-rays, measuring the intensity of fluorescent X-rays of the metal element contained in the component (c), and comparing it with a calibration curve.
本実施形態の高強度亜鉛めっき鋼板の製造方法としては、亜鉛めっき鋼板の表面に無機皮膜を形成する工程と、前記工程で形成した無機皮膜の表面に皮膜（x）を形成する工程を有する製造方法が挙げられる。
The method for producing the high-strength galvanized steel sheet of the present embodiment includes a step of forming an inorganic film on the surface of the galvanized steel sheet, and a step of forming a film (x) on the surface of the inorganic film formed in the step There is a method.
無機皮膜を鋼板表面に形成するには、上記（c）成分を溶媒（主に水）に溶解および／または分散させた表面処理液（無機皮膜形成用表面処理液）を亜鉛めっき鋼板表面に付着させてコーティングした後、乾燥（一般に加熱乾燥）させる方法が採られる。
To form an inorganic coating on the surface of a steel sheet, a surface treatment liquid (surface treatment liquid for forming an inorganic coating) in which the above-mentioned component (c) is dissolved and/or dispersed in a solvent (mainly water) is attached to the surface of the galvanized steel sheet. A method of drying (generally heating and drying) after coating is performed.
前記表面処理液を亜鉛めっき鋼板表面に付着させてコーティングする方法に特別な制限はなく、公知の方法、例えば、塗布方式、浸漬方式、スプレー方式などのいずれかを適用できる。塗布方式では、ロールコーター（３ロール方式、２ロール方式など）、スクイズコーター、ダイコーターなどのいずれの塗布手段を用いてもよい。また、スクイズコーターなどによる塗布処理、浸漬処理、スプレー処理の後に、エアナイフ法やロール絞り法により塗布量の調整、外観の均一化、膜厚の均一化を行うことも可能である。
There is no particular limitation on the method of applying the surface treatment solution to the surface of the galvanized steel sheet for coating, and any known method such as a coating method, a dipping method, or a spray method can be applied. In the coating method, any coating means such as a roll coater (3 roll method, 2 roll method, etc.), a squeeze coater, a die coater or the like may be used. It is also possible to adjust the coating amount, make the appearance uniform, and make the film thickness uniform by an air knife method or a roll squeezing method after the coating treatment using a squeeze coater, the dipping treatment, and the spray treatment.
亜鉛めっき鋼板表面に付着させコーティングした表面処理液を加熱乾燥する方法は任意であり、例えば、ドライヤー、熱風炉、高周波誘導加熱炉、赤外線炉等の手段を用いることができる。
The method of heating and drying the surface treatment liquid that is attached to the surface of the galvanized steel sheet and coated is arbitrary, and for example, a dryer, a hot-air stove, a high-frequency induction heating furnace, an infrared furnace, or the like can be used.
そして、上記のようにして亜鉛めっき鋼板表面に形成した無機皮膜の表面に、皮膜（x）を形成する。皮膜（x）の形成方法は、上述した第一実施形態と同様とすることができる。
Then, a film (x) is formed on the surface of the inorganic film formed on the surface of the galvanized steel sheet as described above. The method of forming the film (x) can be the same as in the above-described first embodiment.
これにより、引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（合金化溶融亜鉛めっき鋼板を含む。）の表面に、所定の無機皮膜を有し、さらにその上に上述の皮膜（x）を有する１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板を製造できる。かかる高強度亜鉛めっき鋼板は、耐遅れ破壊性に優れる。さらに、良好な塗膜密着性を有する。
As a result, the surface of the galvanized steel sheet (including the galvannealed steel sheet) having a tensile strength of 1180 MPa or more has a predetermined inorganic coating, and further has the above-mentioned coating (x) on the surface of 1180 MPa or more. A high-strength galvanized steel sheet having tensile strength can be manufactured. Such a high-strength galvanized steel sheet has excellent delayed fracture resistance. Further, it has good coating film adhesion.
（実施例１）
基材である亜鉛めっき鋼板として、下地鋼板の成分組成がＣ：０．１８質量％、Ｓｉ：１．０質量％、Ｍｎ：３．０質量％、Ｐ：０．００７質量％、Ｓ：０．０００５質量％、残部Ｆｅおよび不可避的不純物からなり、引張強度が１４８０ＭＰａ、板厚が１．６ｍｍの溶融亜鉛めっき鋼板を用いた（ただし、後掲の表２中のNo.４３、No.４４は、それぞれ前記下地鋼板の電気亜鉛めっき鋼板、合金化溶融亜鉛めっき鋼板を用いた）。これらの亜鉛めっき鋼板をトルエンに浸漬して５分間超音波洗浄を行って防錆油を除去した後、表面に樹脂皮膜を形成した。 (Example 1)
As a galvanized steel sheet as a base material, the composition of the base steel sheet is C: 0.18% by mass, Si: 1.0% by mass, Mn: 3.0% by mass, P: 0.007% by mass, S:0. A hot-dip galvanized steel sheet having a tensile strength of 1480 MPa and a plate thickness of 1.6 mm, which was composed of 0.0005% by mass, the balance Fe and unavoidable impurities, was used (however, No. 43 and No. 44 in Table 2 below). Are the electrogalvanized steel sheets and the alloyed hot-dip galvanized steel sheets of the base steel sheet, respectively). These galvanized steel sheets were immersed in toluene and subjected to ultrasonic cleaning for 5 minutes to remove the rust preventive oil, and then a resin film was formed on the surface.
基材である亜鉛めっき鋼板として、下地鋼板の成分組成がＣ：０．１８質量％、Ｓｉ：１．０質量％、Ｍｎ：３．０質量％、Ｐ：０．００７質量％、Ｓ：０．０００５質量％、残部Ｆｅおよび不可避的不純物からなり、引張強度が１４８０ＭＰａ、板厚が１．６ｍｍの溶融亜鉛めっき鋼板を用いた（ただし、後掲の表２中のNo.４３、No.４４は、それぞれ前記下地鋼板の電気亜鉛めっき鋼板、合金化溶融亜鉛めっき鋼板を用いた）。これらの亜鉛めっき鋼板をトルエンに浸漬して５分間超音波洗浄を行って防錆油を除去した後、表面に樹脂皮膜を形成した。 (Example 1)
As a galvanized steel sheet as a base material, the composition of the base steel sheet is C: 0.18% by mass, Si: 1.0% by mass, Mn: 3.0% by mass, P: 0.007% by mass, S:0. A hot-dip galvanized steel sheet having a tensile strength of 1480 MPa and a plate thickness of 1.6 mm, which was composed of 0.0005% by mass, the balance Fe and unavoidable impurities, was used (however, No. 43 and No. 44 in Table 2 below). Are the electrogalvanized steel sheets and the alloyed hot-dip galvanized steel sheets of the base steel sheet, respectively). These galvanized steel sheets were immersed in toluene and subjected to ultrasonic cleaning for 5 minutes to remove the rust preventive oil, and then a resin film was formed on the surface.
樹脂皮膜用の有機樹脂（有機樹脂（a））として下記Ａ１～Ａ４を用い、いずれかの有機樹脂と所定の金属塩（金属塩（b））を含む表面処理液（比較例の一部では有機樹脂のみを含む表面処理液）を、亜鉛めっき鋼板表面に塗布方式（バーコート）、スプレー方式、浸漬方式（およびロール絞り）のいずれかで付着させてコーティングした後、到達板温が１２０℃となるようにインダクションヒーターで加熱することで樹脂皮膜を形成した。
Ａ１：エポキシ樹脂（ジャパンエポキシレジン（株）製、商品名：ｊＥＲ１００９）
Ａ２：アクリル樹脂（ＤＩＣ（株）製、商品名：４０－４１８ＥＦ）
Ａ３：ウレタン樹脂（大日本塗料（株）製、商品名：ＶトップＲＣクリヤー）
Ａ４：フッ素樹脂（旭硝子（株）製、商品名：ルミフロン ＬＦ５５２） The following A1 to A4 were used as the organic resin (organic resin (a)) for the resin film, and a surface treatment liquid containing one of the organic resins and a predetermined metal salt (metal salt (b)) (in some Comparative Examples A surface treatment solution containing only organic resin is applied to the surface of the galvanized steel sheet by any one of a coating method (bar coat), a spray method, and a dipping method (and roll squeezing), and then the reached plate temperature is 120°C. A resin film was formed by heating with an induction heater so that
A1: Epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., trade name: jER1009)
A2: Acrylic resin (manufactured by DIC Corporation, trade name: 40-418EF)
A3: Urethane resin (Dainippon Paint Co., Ltd., trade name: V Top RC Clear)
A4: Fluororesin (Asahi Glass Co., Ltd., trade name: Lumiflon LF552)
Ａ１：エポキシ樹脂（ジャパンエポキシレジン（株）製、商品名：ｊＥＲ１００９）
Ａ２：アクリル樹脂（ＤＩＣ（株）製、商品名：４０－４１８ＥＦ）
Ａ３：ウレタン樹脂（大日本塗料（株）製、商品名：ＶトップＲＣクリヤー）
Ａ４：フッ素樹脂（旭硝子（株）製、商品名：ルミフロン ＬＦ５５２） The following A1 to A4 were used as the organic resin (organic resin (a)) for the resin film, and a surface treatment liquid containing one of the organic resins and a predetermined metal salt (metal salt (b)) (in some Comparative Examples A surface treatment solution containing only organic resin is applied to the surface of the galvanized steel sheet by any one of a coating method (bar coat), a spray method, and a dipping method (and roll squeezing), and then the reached plate temperature is 120°C. A resin film was formed by heating with an induction heater so that
A1: Epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., trade name: jER1009)
A2: Acrylic resin (manufactured by DIC Corporation, trade name: 40-418EF)
A3: Urethane resin (Dainippon Paint Co., Ltd., trade name: V Top RC Clear)
A4: Fluororesin (Asahi Glass Co., Ltd., trade name: Lumiflon LF552)
上記のようにして樹脂皮膜が形成された発明例および比較例の高強度亜鉛めっき鋼板について、以下のようにして耐遅れ破壊性および塗装後耐食性を評価した。その結果を製造条件とともに表１～表３に示す。
With respect to the high-strength galvanized steel sheets of the invention example and the comparative example in which the resin film was formed as described above, the delayed fracture resistance and the corrosion resistance after coating were evaluated as follows. The results are shown in Tables 1 to 3 together with the production conditions.
なお、樹脂皮膜の膜厚の測定では、ＦＩＢ加工により得られた断面をＳＥＭ観察し、任意視野の３箇所で樹脂皮膜の厚さ（基材の亜鉛めっき鋼板面から樹脂皮膜の表面までの厚さ）を測定し、それらの平均値を膜厚とした。また、表中の「その他の粒子成分」（金属塩（b）以外の粒子成分）としては、ＳＵＳ粉（エプソンアトミックス（株）製）、窒化チタン粒子（日本新金属（株）製）を用い、これらの粒子成分の最大粒子径としてはそれぞれの商品のカタログ値を示した。
In the measurement of the film thickness of the resin film, the cross section obtained by FIB processing is observed by SEM, and the thickness of the resin film (thickness from the zinc-plated steel plate surface of the base material to the surface of the resin film is observed at three locations in an arbitrary field of view). Was measured and the average value thereof was taken as the film thickness. Moreover, as "other particle components" (particle components other than the metal salt (b)) in the table, SUS powder (manufactured by Epson Atomix Co., Ltd.) and titanium nitride particles (manufactured by Nippon Shinkin Co., Ltd.) are used. As the maximum particle diameter of these particle components, the catalog value of each product is shown.
（１）耐遅れ破壊性の評価
発明例および比較例の高強度亜鉛めっき鋼板を、それぞれ幅３５ｍｍ×長さ１００ｍｍにせん断した後、せん断時の残留応力を除去するために幅が３０ｍｍとなるまで研削加工を施し、試験片を作製した。この試験片に対して、３点曲げ試験機を用いて１８０°曲げ加工を施し、図１に示すように、内側間隔が８ｍｍとなるようにして曲げ試験片１とし、ボルト２とナット３で拘束して試験片形状を固定し、耐遅れ破壊性評価用試験片を得た。このようにして作製した耐遅れ破壊性評価用試験片に対し、米国自動車技術会で定めたＳＡＥ Ｊ２３３４に規定された、乾燥・湿潤・塩水浸漬の工程からなる複合サイクル腐食試験（図２参照）を、最大４０サイクルまで実施した。各サイクルの塩水浸漬の工程前に目視により割れの発生の有無を調査し、割れ発生サイクルを測定した。また、本試験は、各高強度亜鉛めっき鋼板につき３検体ずつ実施し、その平均値をもって評価を行った。評価はサイクル数から、以下の基準により評価した。なお、表３中の割れ発生サイクル数４０超とは、本実施例の結果では、割れが発生しなかったことを示す。この評価で、◎、〇を評価合格（耐遅れ破壊性に優れる）とし、△、×を評価不合格（耐遅れ破壊性に劣る）とした。
◎：４０サイクル超
〇：３０サイクル以上、４０サイクル以下
△：１０サイクル以上、３０サイクル未満
×：１０サイクル未満 (1) Evaluation of delayed fracture resistance The high-strength galvanized steel sheets of the invention example and the comparative example were each sheared to a width of 35 mm and a length of 100 mm, and then the width became 30 mm in order to remove residual stress during shearing. Grinding was performed to produce a test piece. This test piece was bent 180° using a three-point bending tester, and as shown in FIG. 1, abending test piece 1 was formed so that the inner distance was 8 mm, and a bolt 2 and a nut 3 were used. The shape of the test piece was fixed by restraining it to obtain a test piece for evaluating delayed fracture resistance. The delayed fracture resistance test piece thus produced was subjected to a combined cycle corrosion test consisting of dry, wet, and salt water immersion steps specified in SAE J2334 defined by the American Society of Automotive Engineers (see FIG. 2). Was carried out for up to 40 cycles. Before the salt water immersion step of each cycle, the presence or absence of cracks was visually inspected and the crack generation cycle was measured. In addition, this test was carried out by three samples for each high-strength galvanized steel sheet, and the average value was evaluated. The evaluation was performed based on the number of cycles according to the following criteria. In addition, the number of crack generation cycles of more than 40 in Table 3 indicates that no crack occurred in the results of this example. In this evaluation, ⊚ and ◯ were evaluated as acceptable (excellent in delayed fracture resistance), and Δ and × were evaluated as unacceptable (inferior in delayed fracture resistance).
◎: More than 40 cycles ◯: 30 cycles or more, 40 cycles or less △: 10 cycles or more, less than 30 cycles ×: less than 10 cycles
発明例および比較例の高強度亜鉛めっき鋼板を、それぞれ幅３５ｍｍ×長さ１００ｍｍにせん断した後、せん断時の残留応力を除去するために幅が３０ｍｍとなるまで研削加工を施し、試験片を作製した。この試験片に対して、３点曲げ試験機を用いて１８０°曲げ加工を施し、図１に示すように、内側間隔が８ｍｍとなるようにして曲げ試験片１とし、ボルト２とナット３で拘束して試験片形状を固定し、耐遅れ破壊性評価用試験片を得た。このようにして作製した耐遅れ破壊性評価用試験片に対し、米国自動車技術会で定めたＳＡＥ Ｊ２３３４に規定された、乾燥・湿潤・塩水浸漬の工程からなる複合サイクル腐食試験（図２参照）を、最大４０サイクルまで実施した。各サイクルの塩水浸漬の工程前に目視により割れの発生の有無を調査し、割れ発生サイクルを測定した。また、本試験は、各高強度亜鉛めっき鋼板につき３検体ずつ実施し、その平均値をもって評価を行った。評価はサイクル数から、以下の基準により評価した。なお、表３中の割れ発生サイクル数４０超とは、本実施例の結果では、割れが発生しなかったことを示す。この評価で、◎、〇を評価合格（耐遅れ破壊性に優れる）とし、△、×を評価不合格（耐遅れ破壊性に劣る）とした。
◎：４０サイクル超
〇：３０サイクル以上、４０サイクル以下
△：１０サイクル以上、３０サイクル未満
×：１０サイクル未満 (1) Evaluation of delayed fracture resistance The high-strength galvanized steel sheets of the invention example and the comparative example were each sheared to a width of 35 mm and a length of 100 mm, and then the width became 30 mm in order to remove residual stress during shearing. Grinding was performed to produce a test piece. This test piece was bent 180° using a three-point bending tester, and as shown in FIG. 1, a
◎: More than 40 cycles ◯: 30 cycles or more, 40 cycles or less △: 10 cycles or more, less than 30 cycles ×: less than 10 cycles
（２）塗装後耐食性の評価
発明例および比較例の高強度亜鉛めっき鋼板を１３０ｍｍ×７０ｍｍと１１０ｍｍ×４０ｍｍにせん断して平板試験片とし、この２枚の平板試験片の評価面どうしを重ね合わせてスポット溶接により接合し、図３に示すような耐食性試験用試験片とした。この耐食性試験用試験片に、日本パーカライジング（株）製「パルボンド」を用い、標準条件（３５℃、１２０秒）で浸漬による化成処理を施し、次いで、関西ペイント（株）製の電着塗料「ＧＴ－１００」を用いた電着塗装と焼付処理を行い塗膜を形成した。電着塗装の塗膜厚は１５μｍとし、市販の電磁膜厚計を用いて膜厚の測定を行った。 (2) Evaluation of corrosion resistance after coating The high-strength galvanized steel sheets of the invention examples and comparative examples were sheared to 130 mm x 70 mm and 110 mm x 40 mm to form flat plate test pieces, and the evaluation surfaces of these two flat plate test pieces were superposed on each other. Were joined by spot welding to obtain a corrosion resistance test piece as shown in FIG. This corrosion resistance test piece was subjected to a chemical conversion treatment by immersion under standard conditions (35° C., 120 seconds) using “PALBOND” manufactured by Nippon Parkerizing Co., Ltd., and then an electrodeposition paint manufactured by Kansai Paint Co., Ltd. A coating film was formed by performing electrodeposition coating using "GT-100" and baking treatment. The film thickness of the electrodeposition coating was 15 μm, and the film thickness was measured using a commercially available electromagnetic film thickness meter.
発明例および比較例の高強度亜鉛めっき鋼板を１３０ｍｍ×７０ｍｍと１１０ｍｍ×４０ｍｍにせん断して平板試験片とし、この２枚の平板試験片の評価面どうしを重ね合わせてスポット溶接により接合し、図３に示すような耐食性試験用試験片とした。この耐食性試験用試験片に、日本パーカライジング（株）製「パルボンド」を用い、標準条件（３５℃、１２０秒）で浸漬による化成処理を施し、次いで、関西ペイント（株）製の電着塗料「ＧＴ－１００」を用いた電着塗装と焼付処理を行い塗膜を形成した。電着塗装の塗膜厚は１５μｍとし、市販の電磁膜厚計を用いて膜厚の測定を行った。 (2) Evaluation of corrosion resistance after coating The high-strength galvanized steel sheets of the invention examples and comparative examples were sheared to 130 mm x 70 mm and 110 mm x 40 mm to form flat plate test pieces, and the evaluation surfaces of these two flat plate test pieces were superposed on each other. Were joined by spot welding to obtain a corrosion resistance test piece as shown in FIG. This corrosion resistance test piece was subjected to a chemical conversion treatment by immersion under standard conditions (35° C., 120 seconds) using “PALBOND” manufactured by Nippon Parkerizing Co., Ltd., and then an electrodeposition paint manufactured by Kansai Paint Co., Ltd. A coating film was formed by performing electrodeposition coating using "GT-100" and baking treatment. The film thickness of the electrodeposition coating was 15 μm, and the film thickness was measured using a commercially available electromagnetic film thickness meter.
この電着塗装を施した耐食性試験用試験片に対し、米国自動車技術会で定めたＳＡＥ Ｊ２３３４に規定された、乾燥・湿潤・塩水浸漬の工程からなる複合サイクル腐食試験（図２参照）を３０サイクル実施し、下記の手順で塗装後耐食性の評価を行った。
（1）スポット溶接部を打ち抜き、合わせ構造部を分解する
（2）塗装の剥離（ネオス社製「デスコート３００」１５分浸漬）
（3）めっき・錆の除去（希薄塩酸浸漬）
（4）合わせ構造部に生じた最大侵食深さをポイントマイクロメーターで測定 The corrosion resistance test piece subjected to this electrodeposition coating was subjected to a combined cycle corrosion test (see Fig. 2) consisting of dry, wet, and salt water immersion steps specified in SAE J2334 defined by the American Society of Automotive Engineers. After the cycle, the corrosion resistance after coating was evaluated by the following procedure.
(1) Punch out the spot weld and disassemble the mating structure (2) Peel off the coating (Neos'Deathcoat 300' 15 minutes immersion)
(3) Plating and rust removal (diluted hydrochloric acid immersion)
(4) Maximum erosion depth generated in the mating structure is measured with a point micrometer
（1）スポット溶接部を打ち抜き、合わせ構造部を分解する
（2）塗装の剥離（ネオス社製「デスコート３００」１５分浸漬）
（3）めっき・錆の除去（希薄塩酸浸漬）
（4）合わせ構造部に生じた最大侵食深さをポイントマイクロメーターで測定 The corrosion resistance test piece subjected to this electrodeposition coating was subjected to a combined cycle corrosion test (see Fig. 2) consisting of dry, wet, and salt water immersion steps specified in SAE J2334 defined by the American Society of Automotive Engineers. After the cycle, the corrosion resistance after coating was evaluated by the following procedure.
(1) Punch out the spot weld and disassemble the mating structure (2) Peel off the coating (Neos'Deathcoat 300' 15 minutes immersion)
(3) Plating and rust removal (diluted hydrochloric acid immersion)
(4) Maximum erosion depth generated in the mating structure is measured with a point micrometer
塗装後耐食性は、表面に樹脂皮膜を形成していない亜鉛めっき鋼板の最大侵食深さを１とした場合の最大侵食深さ比（Ａ）を算出し、以下のように評価した。
◎：Ａ≦０．６
○：０．６＜Ａ≦０．９５
△：０．９５＜Ａ≦１．２
×：１．２＜Ａ The corrosion resistance after coating was evaluated as follows by calculating the maximum erosion depth ratio (A) when the maximum erosion depth of the galvanized steel sheet having no resin film formed on its surface was set to 1.
⊚: A≦0.6
◯: 0.6<A≦0.95
Δ: 0.95<A≦1.2
X: 1.2<A
◎：Ａ≦０．６
○：０．６＜Ａ≦０．９５
△：０．９５＜Ａ≦１．２
×：１．２＜Ａ The corrosion resistance after coating was evaluated as follows by calculating the maximum erosion depth ratio (A) when the maximum erosion depth of the galvanized steel sheet having no resin film formed on its surface was set to 1.
⊚: A≦0.6
◯: 0.6<A≦0.95
Δ: 0.95<A≦1.2
X: 1.2<A
表１～表３において、No.１の鋼板は、基材（溶融亜鉛めっき鋼板）表面上に樹脂皮膜を形成していない比較例（溶融亜鉛めっき鋼板ままの比較例）であるが、早期に遅れ破壊が発生しており、耐遅れ破壊性が低いことが判る。
In Tables 1 to 3, the No. 1 steel plate is a comparative example in which a resin film is not formed on the surface of the base material (hot dip galvanized steel plate) (comparative example of the hot dip galvanized steel plate), but It can be seen that delayed fracture has occurred and resistance to delayed fracture is low.
No.３～No.１５の鋼板は、エポキシ樹脂（Ａ１）に金属塩（b）としてトリポリリン酸二水素アルミニウムを混合した表面処理液を塗布方式（バーコート）で溶融亜鉛めっき鋼板表面に塗布し、樹脂皮膜を形成した例である。また、No.２の鋼板は、金属塩（b）が添加されていないエポキシ樹脂（Ａ１）の表面処理液を、同様に塗布して樹脂皮膜を形成した例である。これらのうち、金属塩（b）の含有量の下限が本発明範囲を満たし、かつ本発明の好適な要件を満たすNo.５～No.１４の鋼板は、いずれも優れた耐遅れ破壊性が得られるとともに、塗装後耐食性も良好である。これに対して、金属塩（b）が添加されていないNo.２の鋼板や、金属塩（b）の含有量が本発明範囲を下回るNo.３、No.４の鋼板は、樹脂皮膜を形成していないNo.１の鋼板に比べて、耐遅れ破壊性が若干向上しているが、発明例の鋼板に比べて耐遅れ破壊性が劣っている。また、金属塩（b）の含有量が本発明の好適範囲を超えるNo.１５の鋼板は、塗装後耐食性がNo.５～No.１４の鋼板に比べて低下しており、したがって、通常レベルの塗装後耐食性が要求される用途には特に問題はないが、特に高度な塗装後耐食性が要求される用途には不向きであると言える。
For No. 3 to No. 15 steel plates, a surface treatment solution prepared by mixing epoxy resin (A1) with aluminum dihydrogen tripolyphosphate as a metal salt (b) was applied to the surface of the hot dip galvanized steel plate by a coating method (bar coat). This is an example of forming a resin film. Further, the No. 2 steel plate is an example in which the surface treatment liquid of the epoxy resin (A1) to which the metal salt (b) has not been added is similarly applied to form a resin film. Of these, the steel sheets of No. 5 to No. 14 in which the lower limit of the content of the metal salt (b) satisfies the range of the present invention and satisfy the preferred requirements of the present invention, all have excellent delayed fracture resistance. In addition to being obtained, it has good corrosion resistance after painting. On the other hand, the No. 2 steel plate to which the metal salt (b) is not added and the No. 3 and No. 4 steel plates in which the content of the metal salt (b) is below the range of the present invention have a resin film. Although the delayed fracture resistance is slightly improved as compared to the No. 1 steel sheet that is not formed, the delayed fracture resistance is inferior to the steel sheets of the invention examples. In addition, the steel sheet No. 15 in which the content of the metal salt (b) exceeds the preferred range of the present invention has lower corrosion resistance after painting than the steel sheets No. 5 to No. 14, and therefore the normal level. Although there is no particular problem in the application requiring the post-painting corrosion resistance, it can be said that it is not suitable for the application requiring the high post-painting corrosion resistance.
No.１６、No.１７の鋼板は、No.１１の鋼板に対して樹脂皮膜の成膜法を変えた発明例であるが、いずれも優れた耐遅れ破壊性が得られるとともに、塗装後耐食性も良好である。
The No. 16 and No. 17 steel plates are examples of inventions in which the film forming method of the resin film is changed from that of the No. 11 steel plate, but both have excellent delayed fracture resistance and corrosion resistance after painting. Is also good.
No.１８～No.３１の鋼板は、エポキシ樹脂（Ａ１）に混合する金属塩（b）の種類を変えた発明例であるが、いずれも優れた耐遅れ破壊性が得られるとともに、塗装後耐食性も良好である。
The steel sheets No. 18 to No. 31 are examples of inventions in which the type of the metal salt (b) mixed with the epoxy resin (A1) is changed, and all have excellent delayed fracture resistance and, after coating, Corrosion resistance is also good.
No.３２～No.３７の鋼板は、樹脂皮膜の膜厚を変えた例である。膜厚が本発明範囲であるNo.３３～No.３７の鋼板は、いずれも優れた耐遅れ破壊性が得られるとともに、塗装後耐食性も良好である。これに対して、樹脂皮膜の膜厚が本発明範囲を下回るNo.３２の鋼板は、発明例であるNo.３３～No.３７の鋼板に比べて耐遅れ破壊性が劣っている。さらに塗装後耐食性も劣っている。なお、樹脂皮膜の膜厚が本発明の好適範囲を超えるNo.３７の鋼板は、スポット溶接時に通電せず接合できないことから、溶接性が要求されない用途には特に問題はないが、溶接性が要求される用途には不向きであると言える。
The steel plates No. 32 to No. 37 are examples in which the film thickness of the resin film is changed. The steel sheets No. 33 to No. 37 having a film thickness within the range of the present invention all have excellent delayed fracture resistance and good corrosion resistance after coating. On the other hand, the No. 32 steel sheet having a resin film thickness below the range of the present invention is inferior in delayed fracture resistance to the invention examples No. 33 to No. 37 steel sheets. Furthermore, the corrosion resistance after painting is inferior. The steel plate No. 37 having a resin film thickness exceeding the preferred range of the present invention cannot be joined without being energized during spot welding, so there is no particular problem in applications where weldability is not required, but weldability is It can be said that it is not suitable for the required use.
No.３８～No.４０の鋼板は、有機樹脂の種類を変えた発明例であるが、いずれも優れた耐遅れ破壊性が得られるとともに、塗装後耐食性も良好である。
The steel sheets No. 38 to No. 40 are examples of inventions in which the type of organic resin is changed, but all have excellent delayed fracture resistance and good corrosion resistance after painting.
No.４１、No.４２は、本発明が規定する金属塩（b）（トリポリリン酸二水素アルミニウム）に加えて、膜厚以上の最大粒子径を有する粒径が大きい他の粒子成分（導電性粒子であるＳＵＳ粉、窒化チタン粒子）を皮膜中に添加した比較例であるが、発明例であるNo.１１の鋼板に較べて耐遅れ破壊性が劣っている。
No. 41 and No. 42 are, in addition to the metal salt (b) (aluminum dihydrogen tripolyphosphate) defined by the present invention, other particle components having a maximum particle size equal to or larger than the film thickness and having a large particle size (conductivity Comparative Example in which particles such as SUS powder and titanium nitride particles) are added to the film, but the delayed fracture resistance is inferior to the invention example No. 11 steel sheet.
No.４３、No.４４は、それぞれ基材として電気亜鉛めっき鋼板、合金化溶融亜鉛めっき鋼板を用いた発明例であるが、いずれも優れた耐遅れ破壊性が得られるとともに、塗装後耐食性も良好である。
No. 43 and No. 44 are examples of inventions using an electrogalvanized steel sheet and a galvannealed steel sheet, respectively, as the base material, but both have excellent delayed fracture resistance and corrosion resistance after painting. It is good.
（実施例２）
基材である亜鉛めっき鋼板として、下地鋼板の成分組成がＣ：０．１８質量％、Ｓｉ：１．０質量％、Ｍｎ：３．０質量％、Ｐ：０．００７質量％、Ｓ：０．０００５質量％、残部Ｆｅおよび不可避的不純物からなり、引張強度が１４８０ＭＰａ、板厚が１．６ｍｍの溶融亜鉛めっき鋼板を用いた。この溶融亜鉛めっき鋼板をトルエンに浸漬して５分間超音波洗浄を行って防錆油を除去した後、表面にまず無機皮膜を形成し、その後樹脂皮膜を形成した。 (Example 2)
As a galvanized steel sheet as a base material, the composition of the base steel sheet is C: 0.18% by mass, Si: 1.0% by mass, Mn: 3.0% by mass, P: 0.007% by mass, S:0. A hot-dip galvanized steel sheet having a tensile strength of 1480 MPa and a plate thickness of 1.6 mm was used, which was composed of 0.0005% by mass, the balance Fe and unavoidable impurities. The hot-dip galvanized steel sheet was immersed in toluene and ultrasonically cleaned for 5 minutes to remove the rust preventive oil, and then an inorganic film was first formed on the surface and then a resin film was formed.
基材である亜鉛めっき鋼板として、下地鋼板の成分組成がＣ：０．１８質量％、Ｓｉ：１．０質量％、Ｍｎ：３．０質量％、Ｐ：０．００７質量％、Ｓ：０．０００５質量％、残部Ｆｅおよび不可避的不純物からなり、引張強度が１４８０ＭＰａ、板厚が１．６ｍｍの溶融亜鉛めっき鋼板を用いた。この溶融亜鉛めっき鋼板をトルエンに浸漬して５分間超音波洗浄を行って防錆油を除去した後、表面にまず無機皮膜を形成し、その後樹脂皮膜を形成した。 (Example 2)
As a galvanized steel sheet as a base material, the composition of the base steel sheet is C: 0.18% by mass, Si: 1.0% by mass, Mn: 3.0% by mass, P: 0.007% by mass, S:0. A hot-dip galvanized steel sheet having a tensile strength of 1480 MPa and a plate thickness of 1.6 mm was used, which was composed of 0.0005% by mass, the balance Fe and unavoidable impurities. The hot-dip galvanized steel sheet was immersed in toluene and ultrasonically cleaned for 5 minutes to remove the rust preventive oil, and then an inorganic film was first formed on the surface and then a resin film was formed.
無機皮膜形成用の（c）成分として、表４、表５に記載のシラン化合物またはジルコニウム化合物を含む表面処理液を、亜鉛めっき鋼板表面に、バーコート方式による塗布法で付着させてコーティングした後、到達板温が１２０℃となるようにインダクションヒーターで加熱することで無機皮膜を形成した。（c）成分の片面あたりの付着量の測定は、皮膜表面にＸ線を照射し（c）成分に含まれる金属元素の蛍光Ｘ線の強度を測定し、検量線と比較することで算出した。
After coating a surface treatment liquid containing a silane compound or a zirconium compound shown in Tables 4 and 5 as a component (c) for forming an inorganic film on the surface of a galvanized steel sheet by a coating method using a bar coating method. An inorganic film was formed by heating with an induction heater so that the reached plate temperature was 120°C. The amount of the component (c) deposited on one surface was measured by irradiating the surface of the film with X-rays, measuring the intensity of the fluorescent X-ray of the metal element contained in the component (c), and comparing it with the calibration curve. ..
樹脂皮膜は、上記のようにして形成した無機皮膜の表面に、実施例１と同様の方法で形成した。また、樹脂皮膜の膜厚を、実施例１と同様の方法で測定した。その他の粒子成分としては、実施例１と同様のものを用いた。
The resin film was formed on the surface of the inorganic film formed as described above in the same manner as in Example 1. Further, the film thickness of the resin film was measured by the same method as in Example 1. As the other particle components, those similar to those in Example 1 were used.
（３）耐遅れ破壊性の評価
発明例および比較例の高強度亜鉛めっき鋼板の耐遅れ破壊性の評価を実施例１と同様にして実施した。 (3) Evaluation of delayed fracture resistance Evaluation of delayed fracture resistance of the high-strength galvanized steel sheets of the invention example and the comparative example was performed in the same manner as in Example 1.
発明例および比較例の高強度亜鉛めっき鋼板の耐遅れ破壊性の評価を実施例１と同様にして実施した。 (3) Evaluation of delayed fracture resistance Evaluation of delayed fracture resistance of the high-strength galvanized steel sheets of the invention example and the comparative example was performed in the same manner as in Example 1.
（４）塗膜密着性の評価
発明例および比較例の高強度亜鉛めっき鋼板を１３０ｍｍ×７０ｍｍにせん断して平板試験片とした。この塗膜密着性試験用試験片に、日本パーカライジング（株）製「パルボンド」を用い、標準条件（３５℃、１２０秒）で浸漬による化成処理を施し、次いで、関西ペイント（株）製の電着塗料「ＧＴ－１００」を用いた電着塗装と焼付処理を行い塗膜を形成した。電着塗装の塗膜厚は１５μｍとし、市販の電磁膜厚計を用いて膜厚の測定を行った。 (4) Evaluation of coating film adhesion The high-strength galvanized steel sheets of the invention examples and comparative examples were sheared to 130 mm x 70 mm to obtain flat plate test pieces. This test piece for coating film adhesion test was subjected to chemical conversion treatment by immersion under standard conditions (35° C., 120 seconds) using “PALBOND” manufactured by Nippon Parkerizing Co., Ltd., and then electro-deposited by Kansai Paint Co., Ltd. An electrodeposition coating using the coating composition "GT-100" and a baking treatment were performed to form a coating film. The film thickness of the electrodeposition coating was 15 μm, and the film thickness was measured using a commercially available electromagnetic film thickness meter.
発明例および比較例の高強度亜鉛めっき鋼板を１３０ｍｍ×７０ｍｍにせん断して平板試験片とした。この塗膜密着性試験用試験片に、日本パーカライジング（株）製「パルボンド」を用い、標準条件（３５℃、１２０秒）で浸漬による化成処理を施し、次いで、関西ペイント（株）製の電着塗料「ＧＴ－１００」を用いた電着塗装と焼付処理を行い塗膜を形成した。電着塗装の塗膜厚は１５μｍとし、市販の電磁膜厚計を用いて膜厚の測定を行った。 (4) Evaluation of coating film adhesion The high-strength galvanized steel sheets of the invention examples and comparative examples were sheared to 130 mm x 70 mm to obtain flat plate test pieces. This test piece for coating film adhesion test was subjected to chemical conversion treatment by immersion under standard conditions (35° C., 120 seconds) using “PALBOND” manufactured by Nippon Parkerizing Co., Ltd., and then electro-deposited by Kansai Paint Co., Ltd. An electrodeposition coating using the coating composition "GT-100" and a baking treatment were performed to form a coating film. The film thickness of the electrodeposition coating was 15 μm, and the film thickness was measured using a commercially available electromagnetic film thickness meter.
この電着塗装を施した塗膜密着性試験用試験片に対し、下記の手順で塗膜密着性の評価を行った。
（1）試験面にカッターナイフを用いて、素地（基材である亜鉛めっき鋼板表面）に達する１１本の切り傷を１ｍｍ間隔でつける。
（2）９０°向きを変え、同様に１１本の切り傷をつけ、１００個の碁盤目を作る。
（3）碁盤目部分にセロテープ（（登録商標）、ＮＩＣＨＩＢＡＮ社製、品番ＣＴ－２４）を強く圧着させ、テープの端を４５°の角度で引きはがす。
（4）碁盤目の状態を確認する The coating film adhesion test was performed on the test piece for coating film adhesion test, which had been subjected to this electrodeposition coating, in the following procedure.
(1) Using a cutter knife on the test surface, 11 cuts reaching the base material (the surface of the galvanized steel plate that is the base material) are made at 1 mm intervals.
(2) Change the direction by 90°, make 11 cuts in the same manner, and make 100 squares.
(3) A cellophane tape ((registered trademark), manufactured by NICHIBAN, product number CT-24) is strongly pressure-bonded to the cross-cut portion, and the end of the tape is peeled off at an angle of 45°.
(4) Check the state of the grid
（1）試験面にカッターナイフを用いて、素地（基材である亜鉛めっき鋼板表面）に達する１１本の切り傷を１ｍｍ間隔でつける。
（2）９０°向きを変え、同様に１１本の切り傷をつけ、１００個の碁盤目を作る。
（3）碁盤目部分にセロテープ（（登録商標）、ＮＩＣＨＩＢＡＮ社製、品番ＣＴ－２４）を強く圧着させ、テープの端を４５°の角度で引きはがす。
（4）碁盤目の状態を確認する The coating film adhesion test was performed on the test piece for coating film adhesion test, which had been subjected to this electrodeposition coating, in the following procedure.
(1) Using a cutter knife on the test surface, 11 cuts reaching the base material (the surface of the galvanized steel plate that is the base material) are made at 1 mm intervals.
(2) Change the direction by 90°, make 11 cuts in the same manner, and make 100 squares.
(3) A cellophane tape ((registered trademark), manufactured by NICHIBAN, product number CT-24) is strongly pressure-bonded to the cross-cut portion, and the end of the tape is peeled off at an angle of 45°.
(4) Check the state of the grid
塗膜密着性は、碁盤目の格子の内、塗膜が剥がれた格子数(Ｎ)を測定、さらに塗膜の状態を確認し、以下のように評価した。
◎：Ｎ＝０、かつ、格子の一部も剥がれていない。
○：Ｎ＝０、かつ、カット（切り傷）の交差点においてわずかに剥がれている。
△：１≦Ｎ＜１５
×：１５≦Ｎ The coating film adhesion was evaluated as follows by measuring the number (N) of the grids from which the coating film was peeled off in the grid of the grid and confirming the state of the coating film.
A: N=0, and part of the lattice is not peeled off.
◯: N=0, and there is slight peeling at the intersection of cuts (cuts).
△: 1 ≤ N <15
×: 15≦N
◎：Ｎ＝０、かつ、格子の一部も剥がれていない。
○：Ｎ＝０、かつ、カット（切り傷）の交差点においてわずかに剥がれている。
△：１≦Ｎ＜１５
×：１５≦Ｎ The coating film adhesion was evaluated as follows by measuring the number (N) of the grids from which the coating film was peeled off in the grid of the grid and confirming the state of the coating film.
A: N=0, and part of the lattice is not peeled off.
◯: N=0, and there is slight peeling at the intersection of cuts (cuts).
△: 1 ≤ N <15
×: 15≦N
表４～６において、Ｎｏ．５１の鋼板は、基材（溶融亜鉛めっき鋼板）表面上に樹脂皮膜を形成していない比較例（溶融亜鉛めっき鋼板ままの比較例）であるが、早期に遅れ破壊が発生しており耐遅れ破壊性が低いことがわかる。
In Tables 4 to 6, No. The steel plate of No. 51 is a comparative example in which a resin film is not formed on the surface of the base material (hot dip galvanized steel plate) (comparative example of the hot-dip galvanized steel plate), but delayed fracture occurs early and is delayed. It can be seen that the destructiveness is low.
No.５３～６５の鋼板は、溶融亜鉛めっき鋼板表面に、コーティング法で炭酸ジルコニウムアンモニウムを含有した無機皮膜を形成し、その上層にエポキシ樹脂（Ａ１）に金属塩（b）としてポリリン酸二水素アルミニウムを混合した表面処理液を塗布方式（バーコート）で塗布して皮膜を形成した例である。また、No.５２の鋼板は、金属塩（b）が添加されていないエポキシ樹脂（Ａ１）の表面処理液を、同様に塗布して皮膜を形成した例である。これらのうち、金属塩（b）の含有量の下限が本発明範囲を満たし、かつ本発明の好適な要件を満たすNo.５５～No.６４の鋼板は、いずれも優れた耐遅れ破壊性が得られるとともに、塗膜密着性も良好である。これに対して、金属塩（b）が添加されていないNo.５２の鋼板や、金属塩（b）の含有量が本発明範囲を下回るNo.５３、No.５４の鋼板は、樹脂皮膜を形成していないNo.５１の鋼板に比べて、耐遅れ破壊性が若干向上しているが、発明例の鋼板に比べて耐遅れ破壊性が劣っている。また、金属塩（b）の含有量が本発明の好適範囲を超えるNo.６５の鋼板は、塗膜密着性がNo.５５～No.６４の鋼板に比べて劣化してしまうことから、通常レベルの塗膜密着性が要求される用途には特に問題はないが、特に高度な塗膜密着性が要求される用途には不向きであると言える。
The steel sheets of Nos. 53 to 65 have an inorganic coating containing zirconium ammonium carbonate formed on the surface of a galvanized steel sheet by a coating method, and an epoxy resin (A1) as a metal salt (b) of dihydrogen polyphosphate as an upper layer thereon. This is an example in which a surface treatment liquid mixed with aluminum is applied by a coating method (bar coating) to form a film. The steel plate No. 52 is an example in which the surface treatment liquid of the epoxy resin (A1) to which the metal salt (b) has not been added is similarly applied to form a film. Of these, the steel sheets No. 55 to No. 64, in which the lower limit of the content of the metal salt (b) satisfies the range of the present invention and satisfy the preferred requirements of the present invention, all have excellent delayed fracture resistance. In addition to being obtained, the coating film adhesion is also good. On the other hand, No. 52 steel sheet to which the metal salt (b) is not added, and No. 53 and No. 54 steel sheets in which the content of the metal salt (b) is below the range of the present invention have a resin film. Although the delayed fracture resistance is slightly improved as compared with the No. 51 steel sheet which is not formed, the delayed fracture resistance is inferior to the steel sheet of the invention example. Further, No. 65 steel sheet in which the content of the metal salt (b) exceeds the preferred range of the present invention, the coating film adhesion is deteriorated as compared with No. 55 to No. 64 steel sheet, There is no particular problem in applications where a high level of coating film adhesion is required, but it can be said that it is unsuitable for applications where a particularly high level of coating film adhesion is required.
No.６６、６７の鋼板は、No.６１の鋼板に対して樹脂皮膜の成膜法を変えた発明例であるが、いずれも優れた耐遅れ破壊性が得られるとともに、塗膜密着性も良好である。
The steel sheets No. 66 and 67 are examples of inventions in which the film forming method of the resin coating is changed from that of the steel sheet No. 61, but both have excellent delayed fracture resistance and coating film adhesion. It is good.
No.６８～８１の鋼板は、エポキシ樹脂（Ａ１）に混合する金属塩（b）の種類を変えた発明例であるが、いずれも優れた耐遅れ破壊性が得られるとともに、塗膜密着性も良好である。
Steel sheets No. 68 to 81 are examples of the invention in which the type of the metal salt (b) mixed with the epoxy resin (A1) is changed, and all of them have excellent delayed fracture resistance and coating film adhesion. Is also good.
No.８２～８７の鋼板は、樹脂皮膜の膜厚を変えた例である。膜厚が本発明範囲であるNo.８３～No.８７の鋼板は、いずれも優れた耐遅れ破壊性が得られるとともに、塗膜密着性も良好である。これに対して、樹脂皮膜の膜厚が本発明範囲を下回るNo.８２の鋼板は、発明例であるNo.８３～No.８７の鋼板に比べて耐遅れ破壊性が劣っている。なお、樹脂皮膜の膜厚が本発明の好適範囲を超えるNo.８７の鋼板は、スポット溶接時に通電せず接合できないことから、溶接性が要求されない用途には特に問題はないが、溶接性が要求される用途には不向きであると言える。
The steel sheets No. 82 to 87 are examples in which the film thickness of the resin film is changed. The steel sheets No. 83 to No. 87 having a film thickness within the range of the present invention all have excellent delayed fracture resistance and good coating film adhesion. On the other hand, the No. 82 steel sheet having a resin film thickness below the range of the present invention is inferior in delayed fracture resistance to the invention examples No. 83 to No. 87 steel sheet. The steel plate of No. 87 in which the film thickness of the resin film exceeds the preferred range of the present invention cannot be joined without energization during spot welding, so there is no particular problem in applications where weldability is not required, but weldability is It can be said that it is not suitable for the required use.
No.８８～９０の鋼板は、有機樹脂の種類を変えた発明例であるが、いずれも優れた耐遅れ破壊性が得られるとともに、塗膜密着性も良好である。
The steel sheets Nos. 88 to 90 are examples of inventions in which the type of organic resin is changed, but all of them have excellent delayed fracture resistance and good coating adhesion.
No.９１、９２は、本発明が規定する金属塩（b）（トリポリリン酸二水素アルミニウム）に加えて、膜厚以上の最大粒子径を有する粒径が大きい他の粒子成分（導電性粒子であるＳＵＳ粉、窒化チタン粒子）を皮膜中に添加した比較例であるが、発明例であるNo.６１の鋼板に較べて耐遅れ破壊性が劣っている。
Nos. 91 and 92 are, in addition to the metal salt (b) (aluminum dihydrogen tripolyphosphate) defined by the present invention, other particle components having a maximum particle size equal to or larger than the film thickness and having a large particle size (conductive particles. This is a comparative example in which a certain SUS powder and titanium nitride particles) are added to the film, but the delayed fracture resistance is inferior to the steel sheet of No. 61 which is an example of the invention.
No.９３は、下層の無機皮膜を形成せず、溶融亜鉛めっき鋼板に直接樹脂皮膜を形成した発明例であり、優れた耐遅れ破壊性が得られているが、塗膜密着性が劣位である。また、No.９４～９８は、下層の炭酸ジルコニウムアンモニウム化合物の鋼板片面あたりの付着量を変えた発明例であるが、炭酸ジルコニウムアンモニウムの鋼板片面あたりの付着量が本発明の好適範囲を下回るNo.９４の鋼板は、No.９５～９７に比べ塗膜密着性が劣っている。No.９９～１０１は、下層の無機皮膜中に含まれる化合物を変えた発明例であるが、いずれも良好な耐遅れ破壊性と塗膜密着性が得られている。
No. 93 is an example of the invention in which the resin coating was directly formed on the hot-dip galvanized steel sheet without forming the lower inorganic coating, and although the delayed fracture resistance was excellent, the coating adhesion was poor. is there. Nos. 94 to 98 are invention examples in which the amount of the lower layer zirconium ammonium carbonate compound deposited on one side of the steel sheet was changed, but the amount of zirconium ammonium carbonate deposited on one side of the steel sheet was below the preferred range of the present invention. The .94 steel plate is inferior in coating film adhesion to Nos. 95 to 97. Nos. 99 to 101 are examples of the invention in which the compound contained in the lower inorganic coating was changed, and all of them showed good delayed fracture resistance and good coating adhesion.
１ 曲げ試験片
２ ボルト
３ ナット 1Bending test piece 2 Bolt 3 Nut
２ ボルト
３ ナット 1
Claims (21)
- 引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む。）の表面に皮膜（x）を含む皮膜を有し、
該皮膜（x）は、
有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ前記金属塩（b）以外には最大粒子径が該皮膜（x）の膜厚以上の粒子成分を含有せず、
膜厚が０．３μｍ以上であり、皮膜（x）中での金属塩（b）の含有量が５質量％以上である、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 A galvanized steel sheet having a tensile strength of 1180 MPa or more (however, including galvannealed steel sheet) has a coating containing a coating (x) on the surface,
The film (x) is
It contains an organic resin (a) and a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group and a molybdic acid group, and other than the metal salt (b). Does not contain a particle component having a maximum particle size of at least the film thickness of the film (x),
A high-strength galvanized steel sheet having a film thickness of 0.3 μm or more and a content of the metal salt (b) in the film (x) of 5% by mass or more and having a tensile strength of 1180 MPa or more. - 金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩である、請求項１に記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 The high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to claim 1, wherein the metal salt (b) is a metal salt containing at least one of alkali metal, alkaline earth metal, and aluminum.
- 金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩である、請求項１または２に記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 High-strength zinc having a tensile strength of 1180 MPa or more according to claim 1 or 2, wherein the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group, and a silicic acid group. Plated steel sheet.
- 金属塩（b）の鋼板片面あたりの付着量が５０ｍｇ／ｍ２以上である、請求項１～３のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 The high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any one of claims 1 to 3, wherein an adhesion amount of the metal salt (b) per one surface of the steel sheet is 50 mg/m 2 or more.
- 金属塩（b）がトリポリリン酸二水素アルミニウムであり、
皮膜（x）の膜厚が１．０μｍ以上であり、皮膜（x）中でのトリポリリン酸二水素アルミニウムの含有量が１７～４５質量％である、請求項１～４のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 The metal salt (b) is aluminum dihydrogen tripolyphosphate,
The film thickness of the coating film (x) is 1.0 μm or more, and the content of aluminum dihydrogen tripolyphosphate in the coating film (x) is 17 to 45% by mass. A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more. - 皮膜（x）は、導電性粒子および固体潤滑剤粒子を含有しない、請求項１～５のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any one of claims 1 to 5, wherein the coating (x) does not contain conductive particles and solid lubricant particles.
- 皮膜（x）は、金属塩（b）以外の粒子成分を含有しない、請求項１～６のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 The high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any one of claims 1 to 6, wherein the film (x) does not contain particle components other than the metal salt (b).
- 皮膜（x）中に存在する金属塩（b）の含有量が４０質量％以下である、請求項１～７のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 The high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any one of claims 1 to 7, wherein the content of the metal salt (b) present in the film (x) is 40% by mass or less.
- 皮膜（x）の膜厚が４．０μｍ以下である、請求項１～８のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any one of claims 1 to 8, wherein the film thickness of the film (x) is 4.0 μm or less.
- 引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む。）の表面に皮膜（x）を含む皮膜を有する１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法であって、
該皮膜（x）は、
有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ前記金属塩（b）以外には最大粒子径が該皮膜（x）の膜厚以上の粒子成分を含有せず、
膜厚が０．３μｍ以上であり、皮膜（x）中での金属塩（b）の含有量が５質量％以上であり、
前記皮膜（x）を、
前記有機樹脂（a）と、前記金属塩（b）を含有し、且つ前記金属塩（b）以外には最大粒子径が形成すべき前記皮膜（x）の膜厚以上の粒子成分を含有しない表面処理液を、前記皮膜（x）を形成すべき表面に付着させることにより形成する、１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 A method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which has a coating containing a coating (x) on the surface of a galvanized steel sheet having a tensile strength of 1180 MPa or more (including galvannealed steel sheet). There
The film (x) is
It contains an organic resin (a) and a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group and a molybdic acid group, and other than the metal salt (b). Does not contain a particle component having a maximum particle size of at least the film thickness of the film (x),
The film thickness is 0.3 μm or more, the content of the metal salt (b) in the film (x) is 5% by mass or more,
The film (x)
It contains the organic resin (a) and the metal salt (b), and contains no particle component other than the metal salt (b) with a maximum particle size equal to or larger than the film thickness of the film (x) to be formed. A method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more, which is formed by depositing a surface treatment liquid on the surface on which the film (x) is to be formed. - 金属塩（b）が、アルカリ金属、アルカリ土類金属、アルミニウムのうちの少なくとも１種を含む金属塩である、請求項１０に記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 The method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to claim 10, wherein the metal salt (b) is a metal salt containing at least one of an alkali metal, an alkaline earth metal and aluminum. ..
- 金属塩（b）が、リン酸基、亜リン酸基、ケイ酸基のうちの少なくとも１種を含む金属塩である、請求項１０または１１に記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 The high-strength zinc having a tensile strength of 1180 MPa or more according to claim 10 or 11, wherein the metal salt (b) is a metal salt containing at least one of a phosphoric acid group, a phosphorous acid group, and a silicic acid group. Manufacturing method of plated steel sheet.
- 金属塩（b）の鋼板片面あたりの付着量が５０ｍｇ／ｍ２以上である、請求項１０～１２のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 The method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any one of claims 10 to 12, wherein an adhesion amount of the metal salt (b) on one surface of the steel sheet is 50 mg/m 2 or more.
- 金属塩（b）がトリポリリン酸二水素アルミニウムであり、
皮膜（x）の膜厚が１．０μｍ以上であり、皮膜（x）中でのトリポリリン酸二水素アルミニウムの含有量が１７～４５質量％である、請求項１０～１３のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 The metal salt (b) is aluminum dihydrogen tripolyphosphate,
The film thickness of the coating film (x) is 1.0 μm or more, and the content of aluminum dihydrogen tripolyphosphate in the coating film (x) is 17 to 45% by mass. A method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more. - 皮膜（x）は、導電性粒子および固体潤滑剤粒子を含有しない、請求項１０～１４のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 The method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any one of claims 10 to 14, wherein the film (x) does not contain conductive particles and solid lubricant particles.
- 表面処理液は、金属塩（b）以外の粒子成分を含有しない、請求項１０～１５のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 The method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any of claims 10 to 15, wherein the surface treatment liquid does not contain particle components other than the metal salt (b).
- 皮膜（x）中に存在する金属塩（b）の含有量が４０質量％以下である、請求項１０～１６のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 The method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any one of claims 10 to 16, wherein the content of the metal salt (b) present in the film (x) is 40% by mass or less. ..
- 皮膜（x）の膜厚が４．０μｍ以下である、請求項１０～１７のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 The method for producing a high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more according to any one of claims 10 to 17, wherein the film thickness of the film (x) is 4.0 μm or less.
- 引張強度が１１８０ＭＰａ以上の亜鉛めっき鋼板（但し、合金化溶融亜鉛めっき鋼板を含む。）の遅れ破壊を抑制するための皮膜（x）を含む皮膜を前記亜鉛めっき鋼板の表面に形成するための表面処理液であって、
有機樹脂（a）と、リン酸基、亜リン酸基、ケイ酸基、モリブデン酸基のうちの少なくとも１種を含む金属塩（b）を含有し、且つ前記金属塩（b）以外には最大粒子径が形成すべき前記皮膜（x）の膜厚以上の粒子成分を含有せず、全固形分中での前記金属塩（b）の含有割合が５質量％以上である、表面処理液。 Surface for forming a film including a film (x) for suppressing delayed fracture of galvanized steel sheet having a tensile strength of 1180 MPa or more (including galvannealed steel sheet) on the surface of the galvanized steel sheet A treatment liquid,
It contains an organic resin (a) and a metal salt (b) containing at least one of a phosphoric acid group, a phosphorous acid group, a silicic acid group and a molybdic acid group, and other than the metal salt (b). A surface treatment liquid which does not contain a particle component having a maximum particle size equal to or larger than the film thickness of the film (x) to be formed, and the content ratio of the metal salt (b) in the total solid content is 5% by mass or more. .. - 皮膜が、無機皮膜と前記無機皮膜上に形成された皮膜（x）を含み、
前記無機皮膜は、
シラン化合物、ジルコニウム化合物から選ばれる少なくとも１種（（c）成分）を含有し、前記（c）成分の鋼板片面あたりの付着量が２００～５００ｍｇ／ｍ２である、請求項１～９のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板。 The film includes an inorganic film and a film (x) formed on the inorganic film,
The inorganic film is
10. Any one of claims 1 to 9 containing at least one kind (component (c)) selected from a silane compound and a zirconium compound, and the amount of the component (c) deposited on one side of the steel sheet is 200 to 500 mg/m 2. A high-strength galvanized steel sheet having a tensile strength of 1180 MPa or more as described above. - 皮膜が、無機皮膜と前記無機皮膜上に形成された皮膜（x）を含み、
シラン化合物、ジルコニウム化合物から選ばれる少なくとも１種（（c）成分）を含有する表面処理液を、前記亜鉛めっき鋼板に付着させることにより、前記（c）成分の鋼板片面あたりの付着量が２００～５００ｍｇ／ｍ２である前記無機皮膜を形成し、その後、前記無機皮膜の表面に前記皮膜（x）を形成する、請求項１０～１８のいずれかに記載の１１８０ＭＰａ以上の引張強度を有する高強度亜鉛めっき鋼板の製造方法。 The film includes an inorganic film and a film (x) formed on the inorganic film,
By depositing a surface treatment liquid containing at least one selected from silane compounds and zirconium compounds (component (c)) on the galvanized steel sheet, the amount of the component (c) deposited on one surface of the steel sheet is 200 to The high strength having a tensile strength of 1180 MPa or more according to any one of claims 10 to 18, wherein the inorganic coating having a dose of 500 mg/m 2 is formed, and then the coating (x) is formed on the surface of the inorganic coating. Manufacturing method of galvanized steel sheet.
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| WO2023171143A1 (en) * | 2022-03-08 | 2023-09-14 | Ｊｆｅスチール株式会社 | Steel sheet, plated steel sheet, press-molded article, processed member, production method for press-molded article, and production method for processed member |
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| JP2009120947A (en) * | 2007-10-24 | 2009-06-04 | Nippon Steel Corp | Galvanized steel member having excellent corrosion resistance and weldability and coated steel member having excellent corrosion resistance |
| JP2011219791A (en) * | 2010-04-06 | 2011-11-04 | Nippon Steel Corp | Coated plated steel material for concrete structure |
| JP2013193273A (en) * | 2012-03-16 | 2013-09-30 | Nippon Steel & Sumitomo Metal Corp | Coated steel sheet, and housing using the same |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2009120947A (en) * | 2007-10-24 | 2009-06-04 | Nippon Steel Corp | Galvanized steel member having excellent corrosion resistance and weldability and coated steel member having excellent corrosion resistance |
| JP2011219791A (en) * | 2010-04-06 | 2011-11-04 | Nippon Steel Corp | Coated plated steel material for concrete structure |
| JP2013193273A (en) * | 2012-03-16 | 2013-09-30 | Nippon Steel & Sumitomo Metal Corp | Coated steel sheet, and housing using the same |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2023171143A1 (en) * | 2022-03-08 | 2023-09-14 | Ｊｆｅスチール株式会社 | Steel sheet, plated steel sheet, press-molded article, processed member, production method for press-molded article, and production method for processed member |
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