JPWO2019194229A1 - Zinc-based electroplated steel sheet - Google Patents

Abstract

This zinc-based electroplated steel sheet includes a steel sheet and a zinc-based electroplated layer that is located on at least one surface of the steel sheet and has a hairline that extends in a predetermined direction on the surface. The zinc-based electroplating layer has a three-dimensional average surface roughness Sa (1 μm) h of 200 nm or more and 2000 nm or less and a three-dimensional average surface roughness Sa (1 μm) s of 5 nm or more and 200 nm or less. And a microscopically smooth portion. In the zinc-based electroplating layer, the three-dimensional average surface roughness Sa (50 μm) is continuously measured along a predetermined direction, and the ratio of Sa (50 μm) in the adjacent area formed by two adjacent areas is measured. R50 is calculated, and when the adjacent region where R50 is less than 0.667 or 1.500 or more is set as the adjacent region A, the number ratio of the adjacent regions A is 30% or more.

Description

The present invention relates to a zinc-based electroplated steel sheet.
The present application claims priority based on Japanese Patent Application No. 2018-071944 filed in Japan on April 3, 2018, and the content thereof is incorporated herein.

  Items such as electric devices, building materials, and automobiles that people can see are generally required to have good design. As a method of improving the design, it is common to apply paint to the surface of the article or attach a film, but in recent years, mainly in the Western countries that are nature-oriented, application of materials that utilize the texture of metal Is increasing. From the viewpoint of utilizing the texture of metal, coating or resin coating impairs the texture of metal. Therefore, stainless steel or aluminum which is excellent in corrosion resistance even when unpainted is used as the material of the article. In addition, in order to improve the design of stainless steel materials and aluminum materials, fine arc-shaped irregularities called vibrations or embossing may be applied, but fine linear irregularities called hairlines are added. The appearance is particularly preferred and heavily used.

  The hairline finish (HL finish) is defined as one of the surface finishes of stainless steel materials in JIS G4305: 2012, which is "finished by polishing with an abrasive material of an appropriate grain size so as to have continuous polishing". ing.

  However, since stainless steel materials and aluminum materials are expensive, inexpensive materials that replace these stainless steel materials and aluminum materials are desired. As one of such alternative materials, a metal having a hairline appearance, which has high designability and appropriate corrosion resistance similar to stainless steel materials and aluminum materials and is suitable for use in electric devices and building materials, etc. There are steel materials that have an excellent texture (metallic luster, metallic feeling, hereinafter referred to as “metallic feeling”).

  As a technique for imparting appropriate corrosion resistance to steel materials, a technique for imparting zinc plating or zinc alloy plating, which is excellent in sacrificial corrosion resistance, to steel materials is widely used. As a technique relating to a steel material provided with a hairline design to such zinc plating or zinc alloy plating (hereinafter, zinc plating and zinc alloy plating may be collectively referred to as “zinc-based plating”), for example, hairline An adhesive layer having a light-transmitting property and a film layer-plating layer having a light-transmitting property with respect to the surface of the plating layer having a surface roughness Ra (arithmetic mean roughness) in the direction at right angles to 0.1 to 1.0 μm. (See Patent Document 1 below) and the roughness parameters (Ra and PPI) in the hairline direction and in the direction orthogonal to the hairline formed on the surface layer of the Zn-Al-Mg hot-dip coating layer are specified. And a technique for forming a transparent resin film layer on the surface of a Zn-Al-Mg-based hot-dip coating layer (see Patent Document 2 below), and Zn and Zn-based alloy plating by rolling a texture. To transfer the steel sheet, (see the following Patent Document 3.) Technique to coat the resin as the surface roughness is within a predetermined range has been proposed.

Japanese Registered Utility Model No. 3192959 Japanese Patent Laid-Open No. 2006-124824 Japanese National Publication No. 2013-536901 International Publication No. 2015/125887

  However, with the technique of coating a steel plate provided with a hairline design with an organic resin as proposed in Patent Documents 1 to 3 above, a hairline design can be realized and a certain level of corrosion resistance can be exhibited. However, there is a problem that the metallic coating is lost due to the resin coating.

  Here, as a method of forming a hairline, a steel plate rolling method of rolling a plated steel sheet on which a hairline is desired to be formed by a rolling roll having a predetermined roughness, and a plating grinding method for grinding the surface of the plated steel sheet at which a hairline is desired to be formed. There is. The loss of the metallic feeling as described above was particularly remarkable in the plated steel sheet having the hairline formed by the above-described steel sheet rolling method. Although the reason why the loss of metallic feeling is significant is not clear, in the plated steel sheet produced by the steel sheet rolling method for the hairline, the incident crystal light on the entire surface of the plated layer causes the incident light due to the crystal grains of the plating present on the outermost surface of the plated layer. It is thought that this is due to diffuse reflection at. Therefore, assuming that the surface of the plated steel sheet on which the hairline is formed is coated with a resin as described below, it is considered that the formation of the hairline by the steel sheet rolling method is not appropriate.

  As a method for improving the glossy feeling, a method is known in which a predetermined organic additive is added to the electroplating solution to make the plated crystal grains finer (see, for example, Patent Document 4 above). However, if the crystal grains of the plating are made fine, there is a problem in that, when the upper layer of the plating is coated with resin, the processing adhesion to the resin film is reduced. Further, the method described in Patent Document 4 has a problem in that it is necessary to use an organic substance additive in order to obtain smooth plating, which increases the cost of dragout (waste solution) treatment of the plating solution.

  Since the stainless steel material has good corrosion resistance due to the oxide film existing on the surface thereof, coating for improving the corrosion resistance is unnecessary. That is, since the metal base itself can be used on the surface, the problem of loss of metallic feeling due to the resin coating does not exist in the first place. On the other hand, when the stainless steel material is coated with a resin, the purpose is to give coloring or another texture. Therefore, in the stainless steel material, the loss of metallic feeling as found by the present inventors did not cause a problem. The same applies to the aluminum material.

  In addition, depending on the application, a matte appearance in which glossiness is suppressed while having a metallic feel is preferred as a soothing texture. As described above, the hairline is usually formed by polishing / grinding the surface with a polishing / grinding belt or the like, or rolling with a rolling roll. It is difficult to realize a matte appearance with low gloss because the area where the roughness becomes low due to ().

  Furthermore, a zinc-based plated steel sheet is often coated with a resin in order to maintain corrosion resistance and maintain its aesthetic appearance, but the adhesion between the zinc-based plated layer and the resin coating may decrease with the formation of hairlines. It was

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to suppress an increase in gloss while having a hairline appearance, and to form a resin film on the plating upper layer. In this case, it is to provide a zinc-based electroplated steel sheet capable of achieving high coating adhesion while maintaining a metallic feeling.

The present inventors diligently studied a method for improving the metallic feeling, and if the diffused reflection on the outermost surface of the plating layer can be suppressed, even if the surface of the plating layer is resin-coated, the metallic feeling is improved. Thought that it is possible to improve. As a result of further studies based on such an idea, the present inventors provide a smooth portion having a surface roughness in a microscopic range of a predetermined threshold value or less on the plating layer surface in order to suppress diffused reflection. Then, we came to the knowledge that diffuse reflection can be suppressed.
Further, the inventors of the present invention appropriately adjust the ratio of the rough portion and the smooth portion whose surface roughness in the microscopic range is above a predetermined threshold value on the surface of the plating layer, thereby providing a metallic feeling and coating adhesion. It was possible to obtain the knowledge that an excessive increase in gloss can be suppressed while satisfying both requirements. The “surface roughness in the microscopic range” will be described later.

Based on the above-mentioned various findings, the inventors of the present invention have diligently studied the distribution state of the rough portion and the smooth portion, and in the case where the organic resin coating layer is provided on the zinc-based electroplating layer. The present invention has been completed by conceiving the conditions for suppressing an excessive increase in gloss while achieving both metallic feeling and film adhesion.
The gist of the present invention completed based on such knowledge is as follows.

(1) In the zinc-based electroplated steel sheet according to one aspect of the present invention, a steel sheet and a zinc-based electroplated layer that is located on at least one surface of the steel sheet and has a hairline that extends in a predetermined direction on the surface. The zinc-based electroplating layer is defined by a microscopic rough portion having a three-dimensional average surface roughness Sa (1 μm) h of more than 200 nm and 2000 nm or less defined in (A) below, and defined in (B) below. A three-dimensional average surface roughness Sa (1 μm) s of more than 5 nm and 200 nm or less.
In the zinc-based electroplating layer, the three-dimensional average surface roughness Sa in a region of 50 μm × 50 μm is provided along each of the hairline direction in which the hairline is extended and the hairline orthogonal direction orthogonal to the hairline direction. (50 μm) is continuously measured to calculate R50 which is the ratio of Sa (50 μm) in the adjacent region formed by two adjacent regions, and the R50 is less than 0.667 or 1.500 or more. When the adjacent area is the adjacent area A, the number ratio of the adjacent areas A is 30% or more in both the hairline direction and the hairline orthogonal direction.
(A) Sa (1 μm) h means a roughness profile having a length of 1000 μm in the hairline direction, and the ten highest points of the protrusions among the highest points of the protrusions in the roughness profile. The three-dimensional average surface roughness Sa (1 μm) of a region of 1 μm × 1 μm centering on each of the convex vertices, and the minimum value of the measured three-dimensional average surface roughness Sa (1 μm) Represents
(B) Sa (1 μm) s is a roughness profile having a length of 1000 μm measured in the hairline direction, and 10 concave portions at the lowest position among the concave vertices in the roughness profile, The three-dimensional average surface roughness Sa (1 μm) in a region of 1 μm × 1 μm centering on the apex of each recess is measured, and the maximum value of the measured three-dimensional average surface roughness Sa (1 μm) is shown.
(2) The zinc-based electroplated steel sheet according to (1) may further include, as an upper layer of the zinc-based electroplated layer, a light-transmitting organic resin coating layer having a thickness of 10 μm or less. Good.
(3) In the zinc-based electroplated steel sheet according to (2), the organic resin coating layer contains a colorant, and the color tone of the organic resin coating layer according to the L ^* a ^* b ^* color system is CIE standard. The value of (a ^{* 2} + b ^{* 2} ) ^0.5 indicating the saturation may be 10 or less when measured by the specular reflection light removal method using a color difference meter using the light source D65.
(4) In the zinc-based electroplated steel sheet according to (2) or (3), in a state where the organic resin coating layer is present, a surface roughness Ra (CC) measured along the hairline orthogonal direction, and The surface roughness Ra (MC) of the zinc-based electroplating layer measured along the hairline orthogonal direction after peeling off the organic resin coating layer satisfies the relationship represented by the following formula (1). You may.
Ra (CC) <Ra (MC) <5 × Ra (CC) ... Formula (1)
(5) In the zinc-based electroplated steel sheet according to any one of (1) to (4), the exposure rate of the base iron in the zinc-based electroplated layer may be less than 5%.
The zinc-based electroplated steel sheet according to any one aspect of (6) (1) to (5), the adhesion amount of the zinc-based electroplated layer ^may be a 10g / ^{m 2} ~60g / m 2 .
(7) In the zinc-based electroplated steel sheet according to any one of (1) to (6), the zinc-based electroplated layer or an organic resin coating layer provided as an upper layer of the zinc-based electroplated layer. The surface roughness Ra of the steel sheet after removing both the zinc-based electroplated layer may be 1.0 μm or more and 1.7 μm or less.
(8) In the zinc-based electroplated steel sheet according to any one of (1) to (7), the zinc-based electroplated layer is any one selected from the group consisting of Fe, Ni, and Co. The above elements may be contained in a total amount of 5 to 20% by mass.
(9) In the zinc-based electroplated steel sheet according to any one of (1) to (8), the zinc-based electroplated layer or an organic resin coating layer provided as an upper layer of the zinc-based electroplated layer. The surface roughness Ra of the steel sheet after removing both the zinc-based electroplated layer and the zinc-based electroplated layer may be 60% or less of the thickness of the zinc-based electroplated layer.

  As described above, according to the present invention, it is possible to suppress the excessive increase in gloss while having a hairline appearance and an excellent metallic feel, and to realize film adhesion when a resin film is formed on the upper plating layer. Is possible.

It is explanatory drawing which showed typically an example of the structure of the zinc-based electroplated steel sheet which concerns on embodiment of this invention. It is explanatory drawing which showed typically an example of the structure of the zinc-based electroplated steel sheet which concerns on the same embodiment. It is an example of an image when the surface of the zinc-based electroplated layer of the zinc-based electroplated steel sheet according to the same embodiment is observed with a SEM (scanning electron microscope). It is an example of an image when the surface of the zinc-based electroplated layer of the zinc-based electroplated steel sheet according to the embodiment is observed by a normal camera.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, constituent elements having substantially the same functional configuration are designated by the same reference numerals, and duplicate description will be omitted.

(About the overall structure of zinc-based electroplated steel sheet)
Hereinafter, first, the overall configuration of the zinc-based electroplated steel sheet according to the embodiment of the present invention will be described in detail with reference to FIGS. 1A and 1B. 1A and 1B are explanatory diagrams schematically showing an example of the structure of the zinc-based electroplated steel sheet according to the present embodiment.

  The zinc-based electroplated steel sheet according to the present embodiment has at least a steel sheet that is a base material, and a zinc-based electroplated layer located on one surface of the steel sheet, and the surface of the zinc-based electroplated layer Has been hairline processed.

  In general hairline processing, a smooth portion corresponding to the hairline (that is, a portion crushed by the hairline processing and smoothed) is provided so as to be physically continuous along a predetermined direction. The connection is recognized as a hairline. However, the hairline processing applied to the surface of the zinc-based electroplating layer according to the present embodiment is performed by a person who has a zinc-based electroplating layer according to the present embodiment, although the smooth portion is not physically continuous. When the surface of the is observed, it has a characteristic that it is recognized that the hairline is connected in a predetermined direction. Hereinafter, the zinc-based electroplated steel sheet according to this embodiment having such characteristics will be described in detail.

  As schematically shown in FIG. 1A, the zinc-based electroplated steel sheet 1 according to the present embodiment includes a steel sheet 11 as a base material, a zinc-based electroplated layer 13 located on one surface of the steel sheet 11, and Have at least Further, as shown in FIG. 1B, the zinc-based electroplated steel sheet 1 according to the present embodiment further has a light-transmitting organic resin coating layer 15 on the surface side of the zinc-based electroplated layer 13. It is preferable.

<Substrate>
The steel sheet 11 that is the base material of the zinc-based electroplated steel sheet 1 according to the present embodiment is not particularly limited, and may be a mechanical characteristic (for example, tensile strength) required for the zinc-based electroplated steel sheet. It is possible to appropriately use various known steel plates.

[About the surface shape of the substrate]
In the zinc-based electroplated steel sheet 1 according to this embodiment, the zinc-based electroplated layer 13 or both the organic resin coating layer 15 and the zinc-based electroplated layer 13 located on the upper side of the zinc-based electroplated layer 13 are removed. The surface roughness Ra of the steel sheet 11 after the heating is preferably 1.0 μm or more and 1.7 μm or less. Here, Ra is the arithmetic mean roughness defined in JIS B 0601: 2013. When the surface roughness Ra is less than 1.0 μm, it may be difficult to provide the zinc-based electroplating layer 13 having a surface shape as described in detail below, which is not preferable. When the surface roughness Ra exceeds 1.7 μm, it is recognized that the hairline extends in a predetermined direction even if the zinc-based electroplating layer 13 having a surface shape as described in detail below is provided. It is not preferable because it may become difficult.
In the steel sheet 11 according to this embodiment, the steel sheet after removing the zinc-based electroplating layer 13, or both the organic resin coating layer 15 and the zinc-based electroplating layer 13 located on the upper side of the zinc-based electroplating layer 13 The surface roughness Ra of 11 is more preferably 1.1 μm or more and 1.5 μm or less.
In the present invention, the surface roughness Ra is not significantly different between the direction in which the hairline is visually recognized as being stretched and the direction orthogonal to the hairline, but with respect to the range of the surface roughness Ra. Is measured in the direction perpendicular to the hairline.

Further, the surface roughness Ra of the steel sheet 11 is obtained after removing the zinc-based electroplating layer 13 or both the organic resin coating layer 15 and the zinc-based electroplating layer 13 located on the upper side of the zinc-based electroplating layer 13. In, the thickness is preferably 60% or less of the thickness of the zinc-based electroplating layer 13. If the surface roughness Ra is more than 60% of the thickness of the zinc-based electroplating layer 13, corrosion resistance may be impaired when the zinc-based electroplating layer 13 having a surface shape as described in detail below is provided. It is not preferable because it has properties.
In the steel sheet 11 according to this embodiment, the steel sheet after removing the zinc-based electroplating layer 13, or both the organic resin coating layer 15 and the zinc-based electroplating layer 13 located on the upper side of the zinc-based electroplating layer 13 The surface roughness Ra of 11 is more preferably 40% or less of the thickness of the zinc-based electroplating layer 13.
The thickness of the zinc-based electroplating layer 13 is obtained as follows. First, the plated steel sheet is immersed in an acid solution containing an inhibitor to dissolve the zinc-based electroplating layer 13. Next, the thickness of the zinc-based electroplating layer 13 is converted from the adhesion amount of the zinc-based electroplating layer 13 thus obtained and the specific gravity of the metal contained in the zinc-based electroplating layer 13.

  The surface roughness Ra of the steel sheet 11 after removing the zinc-based electroplating layer 13, or both the organic resin coating layer 15 formed as the upper layer of the zinc-based electroplating layer 13 and the zinc-based electroplating layer 13 is In the above range, the surface roughness Ra of the steel sheet 11 before forming the zinc-based electroplating layer 13 and the organic resin coating layer 15 also falls within the above range.

  The surface roughness Ra as described above can be measured by a stylus type roughness meter. Here, when the surface roughness of the steel sheet 11 is measured after the zinc-based electroplating layer 13 and the organic resin coating layer 15 which will be described later are formed, a zinc-based electroplating agent such as a solvent that does not attack the steel sheet or a remover such as a remover is used. The surface roughness Ra may be measured after removing the plating layer 13 and the organic resin coating layer 15.

<Zinc-based electroplating layer>
A zinc-based electroplating layer is formed on one surface of the steel plate 11 as described above. As shown schematically in FIG. 1A, the zinc-based electroplating layer 13 according to the present embodiment has a smooth portion 103 visually recognized as a hairline that extends in a predetermined direction (direction indicated by an arrow at the bottom of FIG. 1A). And rough portions 101a and 101b that are visually recognized as portions that are not hairlines. Here, in the following description, "the direction in which the hairline is visually recognized as being extended" is abbreviated as "hairline direction" and "the direction orthogonal to the direction in which the hairline is extended and the direction in which the hairline is visually recognized". This is abbreviated as "hairline orthogonal direction".

  In FIG. 1A, the rough portion 101a is a recessed portion and is a portion that is free from the influence of polishing and the like accompanying hairline processing. Further, the rough portion 101b is a portion that remains after the hairline processing in the zinc-based electroplating layer 13 even though the surface thereof is located at a position away from the surface of the steel sheet 11 in the depth direction. The portion 101b is also continuous over a certain range in the hairline direction. In the rough portion 101b of FIG. 1A, it is schematically shown that the rough portion may exist also on the surface portion of the zinc-based electroplating layer 13. The rough portion and the smooth portion will be described in detail below.

[About the type and composition of the zinc-based electroplated layer]
As the zinc-based electroplating layer 13 according to this embodiment, electrozinc plating or electrozinc alloy plating (hereinafter collectively referred to as “zinc-based electroplating”) is used.

  First, regarding plating metal, plating other than zinc-based plating is inferior in sacrificial corrosion resistance, and is not suitable for applications where the cut end face is inevitably exposed during use. Further, when the zinc concentration in the zinc-based electroplating layer 13 becomes too low, the sacrificial anticorrosive ability is lost. Therefore, the zinc alloy plating contains zinc in an amount of 65% by mass or more based on the total mass of the zinc-based electroplating layer 13. Preferably.

As the plating method, in addition to electroplating, there are a hot dipping method, a thermal spraying method, a vapor deposition plating method, and the like. However, the hot dipping method is not suitable because the appearance quality is inferior due to solidification patterns such as spangles and dross inevitably mixed in the plating layer. Further, the thermal spraying method is not suitable because the voids inside the plating film cannot ensure the uniformity of the appearance. Further, the vapor deposition method is unsuitable because the productivity is poor due to the slow film formation rate.
Therefore, in the zinc-based electroplated steel sheet 1 according to this embodiment, electroplating is used to apply zinc-based plating to the steel sheet surface.

  Here, when the zinc-based electroplating layer 13 according to the present embodiment is formed by using electrozinc alloy plating, such electrozinc alloy plating includes Co, Cr, Cu, Fe, Ni, P, Sn, Mn, It is preferable to include Zn and at least one element selected from the element group consisting of Mo, V, W, and Zr. In particular, it is preferable that the electrogalvanic alloy plating contains one or more elements selected from the group of elements consisting of Fe, Ni, and Co in a total amount of 5% by mass or more and 20% by mass or less. When the electrogalvanized alloy contains one or more elements selected from the group of elements consisting of Fe, Ni, and Co within the above total content range, it becomes possible to realize more excellent corrosion resistance. .

  The electrolytic zinc plating and the electrolytic zinc alloy plating may contain impurities. Here, the impurities are not intentionally added as a zinc-based electroplating component but are mixed in the raw material or mixed in the manufacturing process, such as Al, Mg, Si, Ti, B. , S, N, C, Nb, Pb, Cd, Ca, Pb, Y, La, Ce, Sr, Sb, O, F, Cl, Zr, Ag, W, H and the like. Further, when performing electrogalvanizing, depending on the type of electroplated steel sheet manufactured by the same manufacturing facility, Co, Cr, Cu, Fe, Ni, P, Sn, Mn, Mo, V, W and Zr may be mixed as impurities. In the present embodiment, even if the total amount of impurities is about 1% by mass with respect to the total mass of plating, the effect obtained by plating is not impaired.

  In the zinc-based electroplating layer 13 of the present invention, if the Zn content is excessively reduced, the sacrificial anticorrosive ability is reduced. Therefore, the Zn content in the zinc-based electroplating layer 13 is the same as that of the zinc-based electroplating layer 13. It is preferably 65% or more, more preferably 70% or more, and particularly preferably 80% or more with respect to the mass.

  The composition of the zinc-based electroplating layer 13 can be analyzed by the following method, for example. That is, after removing the organic resin coating layer with a release agent such as a solvent or remover (for example, Neo-River S-701: manufactured by Sansai Kako Co., Ltd.) that does not attack plating, a zinc-based electroplating layer is added with hydrochloric acid containing an inhibitor. After melting, the composition of the zinc-based electroplating layer 13 may be analyzed by an ICP (Inductively Coupled Plasma) emission spectroscopy analyzer.

[Regarding Adhesion Amount of Zinc-Based Electroplating Layer 13]
The adhesion amount of the zinc-based electroplating layer according to this embodiment is preferably 10 g / m ² or more. As long as the desired corrosion resistance can be ensured, the adhesion amount of the zinc-based electroplating layer is not limited, but if the adhesion amount of the zinc-based electroplating layer is less than 10 g / m ² , the exposure rate of the base iron is 5% when applying the hairline. It is not preferable because the possibility of exceeding it increases.
The adhesion amount of the zinc-based electroplating layer is more preferably 15 g / m ² or more, and further preferably 20 g / m ² or more. The upper limit of the amount of the zinc-based electroplated layer deposited is not particularly limited, and may be appropriately determined in consideration of the manufacturing cost of the plated steel sheet according to the present embodiment, for example, about 60 g / m ^2. can do.

[About exposure rate of base steel]
The zinc-based electroplated steel sheet 1 according to the present embodiment is premised on that the surface of the zinc-based electroplated layer 13 is subjected to hairline processing such as polishing. Therefore, a part of the zinc-based electroplating layer 13 may be removed in a process step such as polishing, and depending on the polishing / grinding thickness, the base metal (that is, the steel plate 11) may be partially exposed.

It is preferable that the base iron exposure rate of the zinc-based electroplating layer 13 according to the present embodiment is less than 5%. In this embodiment, although corrosion resistance is sufficiently ensured by zinc or zinc alloy plating, if the base iron is exposed at the time of applying the hairline, long-term corrosion resistance may decrease due to the effect of galvanic corrosion, which is not preferable. . In the present embodiment, the zinc-based electroplating layer 13 has a base iron exposure rate of less than 5%, and thus has excellent corrosion resistance because it has excellent long-term corrosion resistance in addition to the appropriate corrosion resistance generally required for steel sheets. .
The exposure rate of the base iron of the zinc-based electroplating layer 13 is more preferably 3% or less, and further preferably 0%.
The base iron exposure rate is an area in which Zn is not detected with respect to the analysis area after the organic resin coating layer 15 is removed with a solvent that does not attack the plating or a release agent such as a remover, and then EPMA analysis is performed on 5 locations on any 1 mm square. The rate can be obtained by image analysis.

  Since the surface of the zinc-based electroplating layer 13 according to the present embodiment is subjected to specific hairline processing, the surface has a characteristic surface shape associated with the hairline processing. The surface shape will be described in detail below again.

<About the organic resin coating layer>
The surface of the zinc-based electroplating layer 13 provided with the hairline as described above is coated with a transparent resin (in other words, a resin having a light-transmitting property) as schematically shown in FIG. 1B. Is preferred. That is, it is preferable that the organic resin coating layer 15 is provided on the surface side of the zinc-based electroplating layer 13 according to the present embodiment. Here, in the present embodiment, “the resin has a light-transmitting property” means that the surface of the zinc-based electroplated steel sheet 1 is illuminated and the zinc-based electroplated steel sheet 1 is observed at an angle of 10 ° from the vertical direction. At this time, it means that the hairline applied to the zinc-based electroplating layer 13 can be visually recognized.

[Components of organic resin coating layer]
The resin used for forming the organic resin coating layer 15 is not particularly limited as long as it has sufficient transparency. Examples of the resin used for forming the organic resin coating layer 15 include polyester resin, epoxy resin, urethane resin, polyester resin, phenol resin, polyether sulfone resin, melamine alkyd resin, and acrylic resin. Examples thereof include resins, polyamide resins, polyimide resins, silicone resins, polyvinyl acetate resins, polyolefin resins, polystyrene resins, vinyl chloride resins and vinyl acetate resins.

  Further, as a means for improving the adhesion between the organic resin coating layer 15 and the zinc-based electroplating layer 13, the steel sheet 11 and the zinc-based electroplating layer 13 are coated with each other within a range that does not impair the appearance. Inorganic treatment, organic-inorganic composite treatment, surface modification treatment and the like may be performed. Here, “impairing the appearance” means reducing a metallic feeling such as a decrease in transparency, uneven gloss, and abnormal unevenness. Examples of such treatment include Zr oxide treatment, Zn oxide treatment, silane coupling agent treatment, weak acid immersion treatment, and weak alkali immersion treatment.

  In order to add desired performances to the organic resin coating layer 15, various additives may be contained within a range that does not impair the translucency and appearance and does not deviate from the range defined by the present invention. . Examples of the performance to be added to the organic resin coating layer 15 include corrosion resistance, slidability, scratch resistance, conductivity, and color tone. For example, if it is corrosion resistant, it may contain a rust inhibitor, an inhibitor, etc., if it is slidable or scratch resistant, it may contain wax, beads, etc., and if it is conductive, it is a conductive agent. Etc. may be contained, and a known colorant such as a pigment or a dye may be contained as long as it has a color tone.

When a known coloring agent such as a pigment or a dye is added to the organic resin coating layer 15 according to the present embodiment, the coloring agent is added to such an extent that the hairline is visible and the metallic feeling is not lost. It is preferable. Here, the degree to which the hairline can be visually recognized and the metallic feeling is not lost means that the color tone (L ^* a ^* b) of the organic resin coating layer 15 is observed in a 10-degree visual field by a commercially available color difference meter using a CIE standard light source D65. ^* Means the range where saturation (a ^{* 2} + b ^{* 2} ) ^0.5 ≤ 10 holds when the color tone of the color system is measured by the SCE (Specular Component Excluded) method. .

[About the thickness of the organic resin coating layer]
The thickness of the organic resin coating layer 15 according to this embodiment is preferably 10 μm or less. When the thickness of the organic resin coating layer 15 exceeds 10 μm, the distance that light passes through the organic resin coating layer 15 becomes long, the reflected light is reduced, and the glossiness in the hairline direction is reduced. As a result, the hairline is hard to be visually recognized. It is not preferable because it is more likely to occur. In addition, it is not preferable because the deformation of the resin accompanying the processing easily causes a deviation between the texture of the surface of the zinc-based electroplating layer 13 and the shape of the surface of the organic resin coating layer 15.
For the above reasons, the thickness of the organic resin coating layer 15 is preferably 10 μm or less, more preferably 8 μm or less.

On the other hand, from the viewpoint of corrosion resistance, the thickness of the thinnest portion (that is, the minimum value of the thickness of the organic resin coating layer 15) as viewed from the cross section of the organic resin coating layer 15 is 0.1 μm or more, and the organic resin coating is The average thickness of the layer 15 is preferably 1.0 μm or more. Here, the “thinnest portion” means the minimum value of the film thickness measured at 20 points at 100 μm intervals by cutting out a 5 mm length at an arbitrary position in a direction orthogonal to the hairline and making a cross-section sample. The "average thickness" means the average of 20 points.
The thickness of the thinnest portion of the organic resin coating layer 15 is more preferably 0.5 μm or more, and the average thickness of the organic resin coating layer 15 is more preferably 3.0 μm or more.

  The overall configuration of the zinc-based electroplated steel sheet 1 according to this embodiment has been described above in detail. 1A and 1B show the case where the zinc-based electroplating layer 13 and the organic resin coating layer 15 are formed on one surface of the steel plate 11, but on two surfaces of the steel plate 11 that face each other. The zinc-based electroplating layer 13 and the organic resin coating layer 15 may be formed on.

(Regarding the surface shape of the zinc-based electroplating layer 13)
Next, the surface shape of the zinc-based electroplating layer 13 according to the present embodiment will be described in detail with reference to FIG. 1A.

As described above, the zinc-based electroplating layer 13 according to this embodiment has the smooth portion 103 forming the hairline and the rough portions 101a and 101b in the surface layer portion. The rough portions 101a and 101b are caused by the microscopic surface shape of the zinc-based electroplating layer 13.
In the present embodiment, the rough portions 101a and 101b are portions where the three-dimensional roughness Sa (1 μm) of the 1 μm × 1 μm microscopic region is more than 200 nm and 2000 nm or less, and the detection frequency of the microscopic rough portions is high. The smooth portion 103 is a portion where the three-dimensional roughness Sa (1 μm) of the microscopic area of 1 μm × 1 μm is more than 5 nm and 200 nm or less, and the microscopic smooth portion is frequently detected.

  Here, the three-dimensional roughness Sa is an arithmetic average height defined by ISO 25178, which is an extension of Ra (arithmetic average height of line) defined by JIS B0601: 2013 on the surface.

  Here, in the present embodiment, the “microscopic rough portion”, the “microscopic smooth portion”, the “rough portions 101a and 101b”, and the “smooth portion 103” are defined as follows.

  First, in the zinc-based electroplating layer 13 according to the present embodiment, a laser microscope having a display resolution in the height direction of 10 nm or more and a display resolution in the width direction of 10 nm or more (that is, the height direction and the width direction). The surface of the zinc-based electroplating layer 13 in a range of 1 cm × 1 cm at a magnification of 500 is observed by using a laser microscope having a display resolution of 1) which is superior to 10 nm. Here, when the observation visual field of the laser microscope is less than 1 cm × 1 cm, a plurality of visual fields may be observed and the surface may be observed by connecting the plural visual fields.

  Next, a region in which the three-dimensional roughness Sa (1 μm) h in the region of 1 μm × 1 μm is more than 200 nm and 2000 nm or less was set as a “microscopic rough portion”. Similarly, a region in which the three-dimensional roughness Sa (1 μm) s of the region of 1 μm × 1 μm becomes more than 5 nm and 200 nm or less due to the formation of the hairline is defined as a “microscopic smooth portion”.

  Here, the above-mentioned three-dimensional roughness Sa (1 μm) h is defined as shown in (A) below, and the three-dimensional roughness Sa (1 μm) s is defined as shown in (B) below.

(A) Sa (1 μm) h is a roughness profile having a length of 1000 μm measured in the hairline direction, and the 10 highest peaks of the highest peaks of the peaks in the profile are respectively measured. The three-dimensional average surface roughness Sa (1 μm) in a 1 μm × 1 μm region centered on the apex of the convex portion is measured, and the minimum value of the measured three-dimensional average surface roughness Sa (1 μm) is shown.
(B) Sa (1 μm) s is a roughness profile having a length of 1000 μm measured in the hairline direction, and the 10 dent vertices at the lowest position among the dent vertices in the profile are each of the pit vertices. The three-dimensional average surface roughness Sa (1 μm) in the area of 1 μm × 1 μm is measured, and the maximum value of the measured three-dimensional average surface roughness Sa (1 μm) is shown.

  1A and 1B which are schematic diagrams, the above definition means that a part of Sa (1 μm) s exceeds 200 nm exists in a part of the smooth portion indicated by reference numeral 103, and reference numerals 101a and 101b. It is not excluded that a portion where Sa (1 μm) h is lower than 200 nm exists in a part of the rough portion indicated by.

In the zinc-based electroplating layer 13 according to the present embodiment, the rough portions 101a and 101b correspond to the portions where the crystal particles of the plating exist as they are in the electrodeposited state or in the state close to the electrodeposited state. The smooth portion 103 corresponds to a portion where the crystal grains of the plating are crushed due to the formation of the hairline, or a portion where the shape of the crystal grains does not exist.
In the zinc-based electroplating layer 13 according to the present embodiment, the rough portions 101a and 101b having a high frequency of existence of minute regions (that is, microscopic rough portions) in which the crystal grains that have been plated remain, and the plating A smooth region 103 having a high frequency of existence of a minute region (that is, a microscopically smooth region) in which the original shape of the crystal grains does not remain is made to exist at an appropriate ratio and position as described later. As a result, the smooth portion 103 achieves an improved metallic feeling, and the rough portions 101a and 101b are preferably provided on the zinc-based electroplating layer 13 and preferably have good adhesion to the processed portion with the organic resin coating layer 15. And to suppress excessive rise in gloss.

  In the following, even when the organic resin coating layer 15 is present in the upper layer of the zinc-based electroplating layer 13, in order to achieve both a suitable metallic feeling and a suitable processed part adhesion and suppression of an excessive increase in gloss, Various conditions required for the zinc-based electroplating layer 13 will be described in detail.

[Distribution state of rough part and smooth part]
In the zinc-based electroplating layer 13 according to the present embodiment, it is not preferable that the smooth portion 103 continuously exists in the hairline direction over a long distance because the gloss becomes too high. On the other hand, when the rough portions 101a and 101b are excessively continuous, the continuity of the hairline is impaired, which is not preferable. Therefore, it is important that the rough portions 101a and 101b divide the smooth portion 103 forming the hairline at an appropriate ratio.

  When the three-dimensional average surface roughness Sa (50 μm) in a region of 50 μm × 50 μm is measured using a laser microscope having a display resolution in the height direction of 10 nm or more and a display resolution in the width direction of 10 nm or more. The three-dimensional average surface roughness Sa (50 μm) of a region where many microscopically smooth portions are present and few microscopically rough portions are present is calculated to be low. On the contrary, the three-dimensional average surface roughness Sa (50 μm) of a region where many microscopic rough parts exist and few microscopic smooth parts exist is calculated to be high. Therefore, when a region having a high three-dimensional average surface roughness Sa (50 μm) or a region having a low three-dimensional average surface roughness Sa (50 μm) is continuous, the smooth portion 103 or the rough portions 101a and 101b are continuous. You can judge that

  Here, “a region having a high three-dimensional average surface roughness Sa (50 μm) or a region having a low three-dimensional average surface roughness Sa (50 μm) is continuous” along the hairline direction or the hairline orthogonal direction. Then, when the three-dimensional average surface roughness Sa (50 μm) is continuously measured, the ratio of the three-dimensional average surface roughness Sa (50 μm) between two adjacent regions (hereinafter sometimes referred to as adjacent regions). It means that the value of R50 is in the range of 0.667 or more and less than 1.500 when R50 is calculated.

In the zinc-based electroplating layer 13 according to the present embodiment, the three-dimensional average surface roughness Sa (50 μm) is measured in the hairline direction at n points, and the three-dimensional average surface roughness Sa (50 μm) in the adjacent area in the hairline direction is measured. When the value of the ratio R50 is calculated at (n-1) points, it is out of the range of 0.667 or more and less than 1.500 (in other words, when the value of the ratio R50 is less than 0.667 or 1.500 or more). The ratio of the number of adjacent regions (the adjacent region having a value of the ratio R50 of less than 0.667 or 1.500 or more may be referred to as an adjacent region A) is 30% or more (that is, The number of regions A) / (n-1) is 0.3 or more). In other words, the ratio of the number of adjacent regions having an R50 of 0.667 or more and less than 1.500 (hereinafter, may be referred to as an adjacent region B) is less than 70%.
When the number ratio of the adjacent regions A in the hairline direction is less than 30% (that is, the number ratio of the adjacent regions B is 70% or more), the smooth portion 103 is too continuous and the gloss is too high, and the organic When the resin coating layer 15 is provided, the adhesion of the processed portion is reduced, or the rough portions 101a and 101b are too continuous to be recognized as a continuous hairline, and the glossiness in the hairline direction is too low. This is not preferable because it impairs the metallic feeling.
On the other hand, there is no upper limit to the number ratio of the adjacent areas A in the hairline direction, and the number ratio may be 100%.
By setting the number ratio of the adjacent regions A in the hairline direction to 30% or more, it is possible to appropriately suppress gloss without impairing the metallic feel and to realize excellent film adhesion. The number ratio is preferably 35% or more, more preferably 40% or more.

Similarly to the hairline direction, the number of adjacent regions A is set to 30% or more in the direction orthogonal to the hairline. Even when the number ratio of the adjacent areas A in the direction orthogonal to the hairline is less than 30%, the smooth portion 103 is too continuous and the gloss becomes too high, and the adhesion of the processed portion when the organic resin coating layer 15 is provided is high. It is not preferable because it is lowered or the rough portions 101a and 101b are too continuous to be recognized as a hairline.
On the other hand, there is no upper limit on the number ratio of the adjacent areas A in the hairline orthogonal direction, and the number ratio may be 100%.
By setting the number ratio to 30% or more, gloss can be appropriately suppressed without impairing the metallic feel, and excellent coating adhesion can be realized.
The number ratio is preferably 35% or more, more preferably 40% or more.

  In the present invention, the proportion of the number of adjacent regions A in the hairline direction and the direction orthogonal to the hairline is 30% or more, and unevenness is imparted to the cross-sectional shape of the zinc-based electroplating layer 13 as shown in FIG. As a method for interrupting the continuity, as will be described later, the polishing / grinding thickness with respect to the steel plate roughness is limited to a predetermined ratio. In addition, as described above, it is preferable that the surface roughness Ra of the steel plate 11 that is the base material is within the specific range.

[Regarding Surface Roughness in Rough Parts 101a and 101b]
As described above, in the zinc-based electroplating layer 13 according to the present embodiment, as a result of the number ratio of the adjacent regions A being 30% or more, there are many microscopic rough portions as described above, and The regions where the number of statically smooth portions are small (that is, the rough portions 101a and 101b) are present at an appropriate ratio. This ensures film adhesion when the organic resin coating layer 15 is provided on the zinc-based electroplating layer 13.

Therefore, the zinc-based electroplating layer 13 according to the present embodiment has an area of 1 μm × 1 μm using a laser microscope having a display resolution in the height direction of 1 nm or more and a display resolution in the width direction of 1 nm or more. When the three-dimensional average surface roughness Sa (1 μm) is measured, Sa (1 μm) h defined in (A) above has a microscopic rough portion that is more than 200 nm and 2000 nm or less.
In the zinc-based electroplated steel sheet 1 according to the present embodiment, as described above, it is preferable that the surface roughness Ra of the steel sheet 11 as the base material be within a specific range. As a result, the electroplating layer is deposited in the valley portions (recesses) of the roughness curve (roughness profile), and the portions are protected from polishing or the like. As a result, at least the rough portions 101a have microscopic rough portions. This is because it is secured.

  Since Sa (1 μm) h of the microscopic rough portion is more than 200 nm and 2000 nm or less, a contact state with the organic resin coating layer 15 capable of realizing excellent coating adhesion can be realized more reliably. can do.

[Regarding surface roughness in smooth part]
Moreover, as mentioned earlier, in the zinc-based electroplated layer 13 according to the present embodiment, the smooth portion 103 is present at an appropriate ratio, so that the zinc-based electroplated steel sheet 1 according to the present embodiment is suitable. Has a metallic feel. Here, in order to realize the effect of improving the metallic feeling by the smooth portion 103, it is preferable that the smooth portion 103 has an appropriate surface roughness and an area having an appropriate width.

  Therefore, for the zinc-based electroplating layer 13 according to the present embodiment, the smooth portion 103 is formed by using a laser microscope having a display resolution in the height direction of 1 nm or more and a display resolution in the width direction of 1 nm or more. When the three-dimensional average roughness Sa (1 μm) in the area of 1 μm × 1 μm is measured, Sa (1 μm) s defined in the above (B) has a microscopic smooth portion of more than 5 nm and 200 nm or less.

  Since the smooth portion 103 has a high detection frequency of the microscopic smooth portion, it is possible to achieve both a suitable metallic feeling and a suitable glossiness.

[Surface roughness of zinc-based electroplated layer before and after formation of organic resin coating layer]
Further, in the zinc-based electroplating layer 13 according to the present embodiment, in the state where the organic resin coating layer 15 is present, the surface roughness Ra (CC) [unit: μm] measured along the direction orthogonal to the hairline, and the organic resin The surface roughness Ra (MC) [unit: μm] of the zinc-based electroplating layer 13 measured along the direction orthogonal to the hairline after the coating layer 15 is peeled off is represented by the following formula (101). It is preferable to satisfy the relationship.

    Ra (CC) <Ra (MC) <5 × Ra (CC) ... Formula (101)

  Here, each Ra in the above formula (101) is an average value of Ra measured at arbitrary 10 points and excluding 2 points on the maximum side and 2 points on the minimum side.

  When the surface roughness Ra (MC) and Ra (CC) satisfy the relationship represented by the above formula (101), it is possible to more reliably realize a metallic feeling while having a hairline appearance.

  The surface roughness Ra (MC) and Ra (CC) more preferably satisfy the relationship represented by the following formula (103).

    1.5 × Ra (CC) <Ra (MC) <3.0 × Ra (CC) ... Formula (103)

  The surface roughness Ra in each direction as described above can be measured by a stylus type roughness meter. Here, when the surface roughness of the zinc-based electroplating layer 13 is measured after forming the organic resin coating layer 15 to be described later, the organic resin coating layer 15 is removed by a solvent that does not attack the plating or a release agent such as a remover. The measurement may be performed after the removal.

  The surface shape of the zinc-based electroplating layer 13 according to the present embodiment has been described above in detail with reference to FIG. 1A.

(About manufacturing method of zinc-based electroplated steel sheet)
Subsequently, a method for manufacturing the zinc-based electroplated steel sheet according to the present embodiment as described above will be briefly described.

Below, first, the manufacturing method of the zinc-based electroplated steel sheet having the structure shown in FIGS. 1A and 1B will be briefly described.
First, a steel sheet whose surface roughness is adjusted to fall within a predetermined range is subjected to degreasing with an alkaline solution and pickling with an acid such as hydrochloric acid or sulfuric acid to form a zinc-based electroplating layer. Here, the surface roughness of the steel sheet can be adjusted by using a known method, for example, a method of rolling and transferring with a roll adjusted so that the surface roughness falls within a desired range, etc. The method of can be used.

As a method of forming the zinc-based electroplating layer 13, a known electroplating method can be used.
As the electroplating bath, for example, a sulfuric acid bath, a chloride bath, a zincate bath, a cyanide bath, a pyrophosphoric acid bath, a boric acid bath, a citric acid bath, other complex baths and combinations thereof can be used.
In the electrolytic zinc alloy plating bath, in addition to Zn ions, one or more single ions or complex ions selected from Co, Cr, Cu, Fe, Ni, P, Sn, Mn, Mo, V, W, and Zr. By adding, it is possible to form an electrozinc alloy plating layer containing a desired amount of Co, Cr, Cu, Fe, Ni, P, Sn, Mn, Mo, V, W, and Zr. It is more preferable to add an additive to the plating bath in order to stabilize the ions in the plating bath and control the characteristics of the plating.

  The composition of the electroplating bath, the temperature, the flow rate, and the current density and energization pattern during plating may be appropriately selected so as to obtain a desired plating composition, and are not particularly limited. Further, the thicknesses of the zinc plating layer and the electrozinc alloy plating layer are controlled by adjusting the current value and the time within the range of the current density at which the zinc plating layer or the electrozinc alloy plating layer has a desired composition. You can

  The hairline according to the present embodiment is formed on the obtained steel plate 11 having the zinc-based electroplating layer 13. Examples of the method of applying a hairline include a method of polishing with a polishing belt, a method of polishing with an abrasive grain brush, and a method of polishing with a polishing / grinding device.

  The depth and frequency of the hairline can be controlled to a desired state by adjusting the grain size of the polishing belt or the abrasive grain brush, the rolling force, the relative speed, and the number of times.

  Here, in the polishing treatment as described above, the recesses in which the crystal particles as they are plated are left as they are, or the recesses are appropriately ground, etc. The rough portions 101a and 101b can be present so as to divide the smooth portion 103 as shown in FIG.

In the zinc-based electroplating layer 13 according to the present embodiment, the polishing / grinding thickness (that is, polishing / grinding rate) at the time of forming the hairline with respect to the surface roughness Ra of the steel sheet 11 is set to 10 to 80%, and The desired hairline can be formed. Here, the polishing / grinding rate means how much the zinc-based electroplating layer 13 is polished / ground with respect to the surface roughness of the steel sheet, and the length in the depth direction with the surface of the zinc-based electroplating layer 13 as a starting point. The amount is The polishing / grinding thickness can be changed by adjusting the grain size of the polishing paper, the rolling force, and the number of polishing times.
By forming the hairline with a polishing / grinding rate of 10 to 80%, the hairline is formed in a state where the unevenness on the surface of the steel plate 11 as the base material remains, so that the smooth portion is physically continuous. Although not, it is possible to form a hairline that appears to be connected in a predetermined direction.
If the polishing / grinding rate is less than 10%, the number of adjacent regions A in the hairline direction and / or the direction orthogonal to the hairline is likely to be less than 30%, which is not preferable. The polishing / grinding rate is 10% or more, preferably 20% or more, and more preferably 30% or more.
If the polishing / grinding ratio exceeds 80%, the number of adjacent regions A in the hairline direction and / or the direction orthogonal to the hairline is likely to be less than 30%, which is not preferable. The polishing / grinding ratio is 80% or less, preferably 70% or less, and more preferably 60% or less.
The surface roughness Ra of the steel plate 11 can be measured by a palpation type roughness meter as described above. Further, the polishing / grinding rate is calculated from the difference in the amount of plating adhered between the two adjoining places, with one having a hairline and the other not having a hairline. In the case of the zinc-based electroplating layer according to the present embodiment, a specific gravity of 7.1 is used when converting the attached amount to the length.

  If necessary, the surface of the zinc-based electroplating layer 13 to which the hairline is applied is coated with an organic resin. Here, the coating material used for forming the organic resin coating layer 15 follows the surface shape of the zinc-based electroplating layer 13 at the moment when it is applied to the zinc-based electroplating layer 13, and once the surface of the zinc-based electroplating layer 13 is covered. It is preferable that the leveling after reflecting the shape is slow. That is, it is desirable that the paint has a low viscosity at a high shear rate and a high viscosity at a low shear rate. Specifically, it has a viscosity of 10 [Pa · s] or more at a shear rate of 0.1 [1 / sec], and a shear viscosity of 0.01 [Pa · s] or less at a shear rate of 1000 [1 / sec]. It is desirable to have

  In order to adjust the shear viscosity within the above range, for example, in the case of a coating material using an aqueous emulsion resin, it can be adjusted by adding a hydrogen-bonding viscosity adjusting agent. Such hydrogen-bonding viscosity modifiers can increase the viscosity of the paint because they are bound to each other by hydrogen bonds at low shear rates, but at high shear rates hydrogen bonds are broken, resulting in a decrease in viscosity. To do. This makes it possible to adjust the shear viscosity according to the desired coating conditions.

  The method for coating the organic resin is not particularly limited, and a known method can be used. For example, using a coating material whose viscosity is adjusted as described above, it may be formed by being dried naturally or baked after being applied by a spraying method, a roll coater method, a curtain coater method, a die coater method or a dipping and pulling method. it can. The drying temperature and the drying time, and the baking temperature and the baking time may be appropriately determined so that the organic resin coating layer 15 to be formed has desired performance. At this time, if the heating rate is slow, the time from the softening point of the resin component to the completion of baking will be long and the leveling will proceed, so the heating rate is preferably high.

(Specific examples of zinc-based electroplating layer)
Subsequently, a specific example of the zinc-based electroplating layer 13 according to the present embodiment formed by the method described above will be briefly described with reference to FIGS. 2A and 2B. FIG. 2A is an example of an image when the surface of the zinc-based electroplated layer of the zinc-based electroplated steel sheet according to the present embodiment is observed by SEM. Further, FIG. 2B is an image taken by a normal camera so that the surface of the zinc-based electroplating layer 13 shown in FIG.

  When the zinc-based electroplating layer 13 is formed by the manufacturing method described above, the zinc-based electroplating layer 13 having the surface shape shown in FIG. 2A can be formed, for example. In the micrograph shown in FIG. 2A, the height direction of the photograph corresponds to the hairline direction, and the width direction of the photograph corresponds to the hairline orthogonal direction. As is clear from the micrograph of FIG. 2A, in the zinc-based electroplating layer 13 according to the present embodiment, the smooth portions 103 are not necessarily continuously connected and distributed along the hairline direction, and the rough portions are not necessarily distributed. It can be seen that they are dispersed in 101.

  However, macroscopically observing the zinc-based electroplated steel sheet 1 including the zinc-based electroplated layer 13 as shown in FIG. 2A, as shown in FIG. 2B, there are innumerable hairlines along the hairline direction. Is recognized as This phenomenon is caused by the rough portions 101 being distributed so as to have a predetermined ratio, as described above.

  Hereinafter, the effects of the present invention will be specifically described with reference to invention examples. Note that the contents of the present invention are not limited by the contents described in the examples below.

As the base material, an annealed and temper-rolled steel sheet having a thickness of 0.6 mm (as a component composition, in mass%, C: 0.05%, Si: 0.001%, Mn: 0.15) %, P: 0.01%, S: 0.01%, sol.Al: 0.04%, and the balance being Fe and impurities. Using the Na ₄ SiO ₄ treatment liquid having a concentration of 30 g / L, the above steel sheet was electrolytically degreased under the conditions of treatment liquid 60 ° C., current density 20 A / dm ² and treatment time 10 seconds, and washed with water. Then, the electrolytically degreased steel sheet was immersed in an aqueous H ₂ SO ₄ solution having a concentration of 50 g / L at 60 ° C. for 10 seconds and further washed with water to perform a pretreatment for plating. The surface roughness Ra (arithmetic mean roughness) of the steel sheet was as shown in the table. Further, a commercially available SUS304 steel plate (B4 bright finished steel plate) having a hairline imparted with # 180 abrasive grains was used as a comparative material (indicated as “No. SUS”). No. With SUS, a zinc-based electroplating layer was not formed, and a hairline was not provided. In addition, No. No organic resin coating layer was formed on SUS.

Next, the above steel sheet was plated as shown in the table to form a zinc-based electroplated layer.
As the zinc-based electroplating layer, a Zn plating film, a Zn-Ni plating film, a Zn-Fe plating film, a Zn-Co plating film, a Zn-Ni-Fe plating film, and a Zn-Co-Mo plating film were used. The conditions for forming each plating film are as follows.

<Zn plating film (No. 1 to 15, 62, 66)>
The Zn plating film uses a plating bath having a pH of 2.0 containing 1.0 M Zn sulfate heptahydrate and 50 g / L anhydrous sodium sulfate at a bath temperature of 50 ° C. and a current density of 50 A / dm ² and the amount of deposition. Was formed by adjusting the plating time so that

<Zn-Ni plating film (No. 16 to 29, 63, 67)>
Mixing of Zn sulfate heptahydrate and Ni sulfate hexahydrate so that the composition described in the column of “plating species” in the table is obtained when plating is performed at a bath temperature of 50 ° C. and a current density of 50 A / dm ^2. The ratio was adjusted. Using a plating bath having a pH of 2.0 containing Zn sulfate heptahydrate and Ni sulfate hexahydrate (total of 1.2 M) adjusted at the above mixing ratio, and anhydrous sodium sulfate 50 g / L, the amount of deposition Was formed by adjusting the plating time so that

<Zn-Fe plating film (No. 30 to 43, 64, 68)>
Zn sulphate heptahydrate and Fe (II) sulphate heptahydrate so as to have the composition described in the column of “plating species” in the table when plated at a bath temperature of 50 ° C. and a current density of 50 A / dm ^2. The mixing ratio with was adjusted. A plating bath having a pH of 2.0 containing Zn sulfate heptahydrate and Fe (II) sulfate heptahydrate (total of 1.2 M) adjusted in the above mixing ratio and 50 g / L of anhydrous sodium sulfate was used. The plating time was adjusted so that the adhesion amount was the value shown in the table.

<Zn-Co plating film (No. 44 to 57, 65, 69)>
A mixture of Zn sulfate heptahydrate and Co sulfate heptahydrate so that the composition described in the column of "plating species" in the table is obtained when plating is performed at a bath temperature of 50 ° C and a current density of 50 A / dm ^2. The ratio was adjusted. Using a plating bath having a pH of 2.0 containing Zn sulfate heptahydrate and Co sulfate heptahydrate (total of 1.2 M) adjusted at the above-mentioned mixing ratio, and anhydrous sodium sulfate 50 g / L, the amount deposited Was formed by adjusting the plating time so that

<Zn-Ni-Fe plating film (No. 58 to 59)>
Zn sulphate heptahydrate, Ni sulphate hexahydrate and Fe sulphate so that the composition is as described in the column of "Plating species" in the table when the bath temperature is 50 ° C and the current density is 50 A / dm ^2. (II) The mixing ratio with heptahydrate was adjusted. PH 2 including Zn sulfate heptahydrate, Ni sulfate sulfate hexahydrate, Fe (II) sulfate heptahydrate (total of 1.2M) and 50 g / L of anhydrous sodium sulfate, which are adjusted by the above mixing ratio. It was formed by using a plating bath of 0.0 and adjusting the plating time so that the adhered amount would be the value shown in the table.

<Zn-Co-Mo plating film (No. 60 to 61)>
Zn sulphate heptahydrate, Co sulphate heptahydrate and molybdic acid so that the composition is as described in the column of "plating species" in the table when the bath temperature is 50 ° C and the current density is 50 A / dm ^2. The mixing ratio with sodium dihydrate was adjusted. Zn sulfate heptahydrate, Co sulfate heptahydrate and sodium molybdate dihydrate (1.2M in total) adjusted with the above mixing ratio, sodium formate 25 g / L, and boric acid 50 g / L, It was formed by using a plating bath containing pH of 4.0 and adjusting the plating time so that the adhered amount would be the value shown in the table.

  In all of the above plating treatments, the plating solution was caused to flow so that the relative flow rate was 1 m / sec.

<Measurement of plating film composition>
The composition of the obtained plating film was confirmed by immersing the plated steel sheet in 10 mass% hydrochloric acid containing an inhibitor (NO.700AS manufactured by Asahi Chemical Industry Co., Ltd.) to dissolve and peel it off, and analyze the dissolved solution by ICP.

  As the above reagents, general reagents were used.

<Formation of hairline>
A hairline was applied to the obtained plated steel sheet along the L direction (rolling direction) of the steel sheet. The hairline was formed by pressing abrasive paper against a steel plate. The grain size of the polishing paper, the pressing force, and the number of times of polishing were adjusted to form a hairline so that the polishing / grinding ratio shown in the table was obtained.
As for the polishing / grinding rate, the hairline was applied to one of the two 100 mm widths adjacent to the width direction of the steel sheet, and the coating amount of each was determined without applying the hairline to the other side. It was calculated from the difference between the coating weight and the coating weight after applying the other hairline. The plating specific gravity at this time was 7.1.
The plating roughness and the coating adhesion amount after applying the hairline are as shown in the table.

<Measurement of surface roughness Ra>
The surface roughness Ra of the steel sheet after removing the plating layer is measured by a three-dimensional surface roughness measuring device (Surfcom 1500DX3 manufactured by Tokyo Seimitsu Co., Ltd.), and the three-dimensional surface roughness Sa of the plated steel sheet is a display resolution in the height direction. Was 1 nm or more and the display resolution in the width direction was 1 nm or more, and the measurement was performed according to the above method using a laser microscope / VK-9710 manufactured by KEYENCE CORPORATION.

<Measurement of coating amount of plating layer before applying hairline>
The amount of coating adhered before applying the hairline was calculated from the weight difference before and after dissolution and peeling by immersing the steel sheet after forming the plating layer in 10 mass% hydrochloric acid containing an inhibitor (NO.700AS manufactured by Asahi Kagaku).

<Measurement of microscopic rough portion Sa _A and microscopic smooth portion Sa _B >
The microscopic rough portion Sa _A in each table was obtained as follows. First, using the laser microscope used for measuring the three-dimensional surface roughness Sa, a roughness profile having a length of 1000 μm in the hairline direction was measured. Sa (1 μm) in a region of 1 μm × 1 μm centering on the apex of the 10 protrusions at the highest position among the apexes of the profile was measured. The minimum value among them (that is, the value of Sa (1 μm) h) is shown as Sa _A in the table.
The microscopic smooth portion Sa _B in each table was obtained as follows. First, a height profile having a length of 1000 μm in the hairline direction was measured using the laser microscope used for measuring Sa. Sa (1 μm) in a region of 1 μm × 1 μm centered on the apex of the concave portion was measured for 10 concave apex points at the lowest position among the apex portions of the profile. The maximum value among them (that is, the value of Sa (1 μm) s) is described as Sa _B in the table.

<Measurement of R50>
The three-dimensional average surface roughness Sa (50 μm) in a region of 50 μm × 50 μm was continuously measured at 21 points in the hairline direction and 21 points in the hairline orthogonal direction. The ratio R50 of the three-dimensional average surface roughness Sa (50 μm) in the adjacent areas was calculated in a total of 20 adjacent areas. Among the 20 adjacent regions in total, the number ratio of the adjacent regions A having R50 of less than 0.667 or 1.500 or more is shown in each table.

<Measurement of coating amount of plating layer after applying hairline>
The adhesion amount of the plating layer after applying the hairline was measured in the same manner as the adhesion amount of the plating layer before applying the hairline.
Here, the difference in the adhesion amount of the plating layer before and after applying the hairline corresponds to the reduction amount of the plating layer in the process of applying the hairline.

<Measurement of exposure rate of base steel>
The plated steel sheet obtained by the above-described manufacturing method was cut out, and the image was analyzed by EPMA (JXA8230 manufactured by JEOL Ltd.) in 5 fields of view of 1 mm square. By the image analysis, the region where Zn was not detected and Fe was detected was considered to have exposed the ground iron, and the area ratio of the region was defined as the ground iron exposed ratio. The EPMA analysis was performed under the conditions of an acceleration voltage of 15 kV and an irradiation current of 30 nA. It was judged that Zn was not detected in a region where the detected intensity of Zn was 1/16 or less of that in the case of measuring the standard sample (pure Zn), and 14 / of the case where the detected intensity of Fe was measured in the standard sample (pure Fe) It was determined that Fe was detected in a region exceeding 16.

  The obtained results are shown in the table.

<Formation of organic resin coating layer>
A transparent organic resin coating layer was formed on the above-mentioned plated steel sheet provided with a hairline. As the treatment liquid for forming an organic resin, treatment liquids having various concentrations and viscosities in which a urethane resin (HUX-232, manufactured by ADEKA CORPORATION) was dispersed in water were used. The treatment liquid was scooped up with a roll and transferred to a plated steel sheet so as to have the thickness shown in the table after baking and drying. The plated steel sheet to which the treatment liquid was transferred was placed in a furnace kept at 250 ° C, held for 1 minute to 5 minutes until the ultimate temperature of the steel sheet reached 210 ° C, then taken out and cooled. In addition, No. For Nos. 62 to 69, carbon black (manufactured by Mitsubishi Chemical: # 850) and cyanine blue (manufactured by Dainichiseika: AF Blue E-2B) were added as colorants to the organic resin coating layer.

<Preparation of treatment liquid for forming organic resin>
BYK-425 (manufactured by Big Chemie) was added to the treatment liquid for forming an organic resin as a viscosity modifier, and the viscosity was 10 [Pa · s] or more at a shear rate of 0.1 [1 / sec], and a shear rate of 1000 [ 1 / sec] was adjusted so as to have a shear viscosity of 0.01 [Pa · s] or less. In addition, the viscosity adjusting agent is not added only to the processing liquids corresponding to the conditions 6, 9, 25, 39 and 53, and the viscosity at the shear rate of 0.1 [1 / sec] is adjusted to be less than 10 [Pa · s]. did.

<Measurement of surface roughness Ra (CC) of organic resin coating layer>
The surface roughness Ra (CC) of the organic resin coating layer was measured by a three-dimensional surface roughness measuring device (Surfcom 1500DX3 manufactured by Tokyo Seimitsu Co., Ltd.), similarly to the measurement of the surface roughness Ra of the steel sheet after removing the plating layer. .

<Measurement of glossiness>
The 60 ° gloss G60 of the plated steel sheet after the formation of the organic resin coating layer is measured by a gloss meter (manufactured by Suga Test Instruments: gloss meter UGV-6P) in the L direction (rolling direction of the steel sheet) and the C direction (direction perpendicular to the rolling direction). ). The obtained G60 value is shown in the table.
When the glossiness G60 (Gl) measured in the hairline direction (which represents the same direction as the L direction because the hairline is formed along the L direction in the sample used) is 70 or more and 150 or less, an appropriate glossiness is obtained. It was judged that it was obtained.

<Evaluation of translucency>
The translucency of the zinc-based electroplated steel sheet after the formation of the organic resin coating layer was evaluated by the following method.
The zinc-based electroplated steel sheet after the formation of the organic resin coating layer was irradiated with light from a fluorescent lamp from an angle of 45 °, and the steel sheet was observed from a distance of 15 cm at an angle of 10 ° from the vertical direction. The translucency was evaluated by the standard. Those evaluated as A or B were accepted. The results obtained are shown in the table.

(Evaluation criteria)
A: A hairline with a length of 20 mm or more can be clearly seen. B: A hairline with a length of 20 mm or more whose contour is unclear can be seen. C: A hairline with a length of 20 mm or more cannot be seen. D: A hairline cannot be seen at all.

<Evaluation of coating adhesion>
The coating adhesion of the zinc-based electroplated steel sheet after forming the organic resin coating layer was evaluated by the following method.
A test piece having a width of 50 mm and a length of 50 mm was prepared from the zinc-based electroplated steel sheet after forming the organic resin coating layer. After bending the obtained test piece by 180 °, a tape peeling test was performed on the outside of the bent portion. The appearance of the tape peeling portion was observed with a magnifying glass having a magnification of 10 and evaluated according to the following evaluation criteria. The bending process was performed in an atmosphere of 20 ° C. with a 0.5 mm spacer interposed therebetween. Those evaluated as A or B were accepted. The results obtained are shown in the table.
In addition, No. In SUS, since the organic resin coating layer was not formed, the film adhesion was not evaluated. Therefore, No. The evaluation result of the film adhesion of SUS is shown by "-".

(Evaluation criteria)
A: No peeling of the organic resin coating layer and / or zinc-based electroplating layer was found on the adhesive surface of the tape B: Peeling of the organic resin coating layer and / or zinc-based electroplating layer on a very small part of the adhesive surface of the tape Is observed (peeling area ≤ 2%)
C: Peeling of the organic resin coating layer and / or the zinc-based electroplating layer was observed on a part of the adhesive surface of the tape (2% <peeling area ≦ 20%)
D: Peeling of the organic resin coating layer and / or the zinc-based electroplating layer was observed on the adhesive surface of the tape (peeling area> 20%)

<Evaluation of corrosion resistance>
When evaluating the corrosion resistance (more specifically, long-term corrosion resistance) of the zinc-based electroplated steel sheet after forming the organic resin coating layer, first, the obtained sample was cut into a size of 75 mm × 100 mm, and the end surface and the back surface were cut. Protected with tape seal. The sample in which the end surface and the back surface were protected with a tape seal was subjected to a salt spray test of 35 ° C.-5% NaCl (JIS Z 2371: 2015). A sample having a rust occurrence rate of 5% or less after 240 hours was OK, and a sample having a rust occurrence rate of more than 5% was NG. The results obtained are shown in the table.

<Evaluation of metallic feeling>
The metallic feeling of the zinc-based electroplated steel sheet after the formation of the organic resin coating layer was evaluated by the following method.
Values of glossiness G60 (Gl) measured in the hairline direction and G60 (Gc) measured in the hairline orthogonal direction, and a CIE standard light source D65 condition using a spectrocolorimeter (manufactured by Konica Minolta: CM-2600d) Using the values of a ^* and b ^* measured by the SCE (Specular Component Excluded) method for the color tone of the L ^* a ^* b ^* color system, the metallic feeling was evaluated according to the following evaluation criteria. Those evaluated as A or B were accepted. The results obtained are shown in the table.

(Evaluation criteria)
A: 0.3 ≦ Gc / Gl ≦ 0.75 and (a ^{* 2} + b ^{* 2} ) ^0.5 ≦ 5
B: 0.3 ≦ Gc / Gl ≦ 0.85 and 5 <(a ^{* 2} + b ^{* 2} ) ^0.5 ≦ 10, or 0.75 <Gc / Gl ≦ 0.85 and (a ^{* 2} + b ^{*) 2} ) ^0.5 ≦ 10
C: 0.3> Gc / Gl, or Gc / Gl> 0.85, or 10 <(a ^{* 2} + b ^{* 2} ) ^0.5

  As is clear from Tables 1 to 6, the zinc-based electroplated steel sheets corresponding to the examples of the present invention have excellent translucency and moderate gloss, while having an excellent metallic feel and coating. It can be seen that it has adhesiveness. On the other hand, in the zinc-based electroplated steel sheet corresponding to the comparative example of the present invention, excellent results could not be obtained in at least one of the items of translucency, glossiness, metallic feeling, and coating adhesion.

  The preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, but the present invention is not limited to these examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Zinc-based electroplated steel sheet 11 Steel sheet 13 Zinc-based electroplated layer 15 Organic resin coating layer 101a, 101b Rough part 103 Smooth part

(1) In the zinc-based electroplated steel sheet according to one aspect of the present invention, a steel sheet and a zinc-based electroplated layer that is located on at least one surface of the steel sheet and has a hairline that extends in a predetermined direction on the surface. with Ru.
In the zinc-based electroplating layer, the three-dimensional average surface roughness Sa in a region of 50 μm × 50 μm is provided along each of the hairline direction in which the hairline is extended and the hairline orthogonal direction orthogonal to the hairline direction. (50 μm) is continuously measured to calculate R50 which is the ratio of Sa (50 μm) in the adjacent region formed by two adjacent regions, and the R50 is less than 0.667 or 1.500 or more. When the adjacent area is the adjacent area A, the number ratio of the adjacent areas A is 30% or more in both the hairline direction and the hairline orthogonal direction .
(2) The zinc-based electroplated steel sheet according to (1) may further include, as an upper layer of the zinc-based electroplated layer, a light-transmitting organic resin coating layer having a thickness of 10 μm or less. Good.
(3) In the zinc-based electroplated steel sheet according to (2), the organic resin coating layer contains a colorant, and the color tone of the organic resin coating layer according to the L * a * b * color system is CIE standard. The value of (a * 2 + b * 2) 0.5 indicating the saturation may be 10 or less when measured by the specular reflection light removal method using the color difference meter using the light source D65.
(4) In the zinc-based electroplated steel sheet according to (2) or (3), in a state where the organic resin coating layer is present, a surface roughness Ra (CC) measured along the hairline orthogonal direction, and The surface roughness Ra (MC) of the zinc-based electroplating layer measured along the hairline orthogonal direction after peeling off the organic resin coating layer satisfies the relationship represented by the following formula (1). You may.
Ra (CC) <Ra (MC) <5 × Ra (CC) ... Formula (1)
(5) In the zinc-based electroplated steel sheet according to any one of (1) to (4), the exposure rate of the base iron in the zinc-based electroplated layer may be less than 5%.
The zinc-based electroplated steel sheet according to any one aspect of (6) (1) to (5), the adhesion amount of the zinc-based electroplated layer ^may be a 10g / ^{m 2} ~60g / m 2 .
(7) In the zinc-based electroplated steel sheet according to any one of (1) to (6), the zinc-based electroplated layer or an organic resin coating layer provided as an upper layer of the zinc-based electroplated layer. The surface roughness Ra of the steel sheet after removing both the zinc-based electroplated layer may be 1.0 μm or more and 1.7 μm or less.
(8) In the zinc-based electroplated steel sheet according to any one of (1) to (7), the zinc-based electroplated layer is any one selected from the group consisting of Fe, Ni, and Co. The above elements may be contained in a total amount of 5 to 20% by mass.
(9) In the zinc-based electroplated steel sheet according to any one of (1) to (8), the zinc-based electroplated layer or an organic resin coating layer provided as an upper layer of the zinc-based electroplated layer. The surface roughness Ra of the steel sheet after removing both the zinc-based electroplated layer and the zinc-based electroplated layer may be 60% or less of the thickness of the zinc-based electroplated layer.

When the three-dimensional average surface roughness Sa (50 μm) in a region of 50 μm × 50 μm is measured using a laser microscope having a display resolution in the height direction of 10 nm or more and a display resolution in the width direction of 10 nm or more. When the region having a high three-dimensional average surface roughness Sa (50 μm) or the region having a low three-dimensional average surface roughness Sa (50 μm) is continuous, the smooth portion 103 or the rough portions 101a and 101b are continuous. You can judge that

[Regarding Surface Roughness in Rough Parts 101a and 101b]
As described above, the zinc-based electroplated layer 13 according to the present embodiment, by making the ratio of the number of adjacent areas A to 30% or more, the organic resin coating layer 15 is provided on an upper layer of the zinc-based electroplated layer 13 The film adherence is ensured when it is exposed.

Claims (9)

Steel plate;
A zinc-based electroplating layer that is located on at least one surface of the steel sheet and has a hairline that extends in a predetermined direction on the surface;
Equipped with
The zinc-based electroplating layer,
A microscopic rough portion having a three-dimensional average surface roughness Sa (1 μm) h defined by the following (A) of more than 200 nm and 2000 nm or less;
A microscopic smooth portion having a three-dimensional average surface roughness Sa (1 μm) s defined by the following (B) of more than 5 nm and 200 nm or less;
Have
In the zinc-based electroplating layer, the three-dimensional average surface roughness Sa in a region of 50 μm × 50 μm is provided along each of the hairline direction in which the hairline is extended and the hairline orthogonal direction orthogonal to the hairline direction. (50 μm) is continuously measured to calculate R50 which is the ratio of Sa (50 μm) in the adjacent region formed by two adjacent regions, and the R50 is less than 0.667 or 1.500 or more. When the adjacent area is the adjacent area A, the zinc-based electroplated steel sheet is characterized in that the number ratio of the adjacent areas A is 30% or more in both the hairline direction and the hairline orthogonal direction. .
(A) Sa (1 μm) h means a roughness profile having a length of 1000 μm in the hairline direction, and the ten highest points of the protrusions among the highest points of the protrusions in the roughness profile. The three-dimensional average surface roughness Sa (1 μm) of a region of 1 μm × 1 μm centering on each of the convex vertices, and the minimum value of the measured three-dimensional average surface roughness Sa (1 μm) Represents
(B) Sa (1 μm) s is a roughness profile having a length of 1000 μm measured in the hairline direction, and 10 concave portions at the lowest position among the concave vertices in the roughness profile, The three-dimensional average surface roughness Sa (1 μm) in a region of 1 μm × 1 μm centering on the apex of each recess is measured, and the maximum value of the measured three-dimensional average surface roughness Sa (1 μm) is shown. The zinc-based electroplated steel sheet according to claim 1, further comprising, as an upper layer of the zinc-based electroplated layer, a light-transmitting organic resin coating layer having a thickness of 10 μm or less. The organic resin coating layer contains a colorant,
When the color tone of the L ^* a ^* b ^* color system of the organic resin coating layer is measured by a specular reflection removal method using a color difference meter using a CIE standard light source D65, the saturation is shown (a ^{* 2} The value of + b ^{* 2} ) ^0.5 is 10 or less, The zinc type electroplated steel sheet of Claim 2 characterized by the above-mentioned. In a state where the organic resin coating layer is present, the surface roughness Ra (CC) measured along the hairline orthogonal direction, and after peeling the organic resin coating layer, the measurement along the hairline orthogonal direction. The zinc-based electroplated steel sheet according to claim 2 or 3, characterized in that the surface roughness Ra (MC) of the zinc-based electroplated layer satisfies the relationship represented by the following formula (1). .
Ra (CC) <Ra (MC) <5 × Ra (CC) ... Formula (1) The zinc-based electroplated steel sheet according to any one of claims 1 to 4, wherein the exposure rate of the base iron of the zinc-based electroplated layer is less than 5%. Adhering amount of the zinc-based electroplated ^layer, characterized in that it is a ^{10g / m 2 ~60g / m 2} , zinc-based electroplated steel sheet according to any one of claims 1 to 5. The surface roughness Ra of the steel sheet after removing the zinc-based electroplated layer, or both the organic resin coating layer provided as the upper layer of the zinc-based electroplated layer and the zinc-based electroplated layer is 1. It is 0 micrometer or more and 1.7 micrometers or less, The zinc type electroplated steel plate in any one of Claims 1-6 characterized by the above-mentioned. The zinc-based electroplating layer contains any one or more elements selected from the group consisting of Fe, Ni, and Co in a total amount of 5% by mass to 20% by mass. The zinc-based electroplated steel sheet according to claim 1. The surface roughness Ra of the steel sheet after removing both the zinc-based electroplating layer or the organic resin coating layer provided as an upper layer of the zinc-based electroplating layer and the zinc-based electroplating layer is the zinc The zinc-based electroplated steel sheet according to any one of claims 1 to 8, which is 60% or less of the thickness of the system-based electroplated layer.