KR20190099536A - Zinc-based electroplated steel sheet - Google Patents

Abstract

In this zinc-based electroplated steel sheet, a zinc-based electroplated layer is composed of a rough portion A and a smooth portion B. FIG. The rough portion A includes a region having an average surface roughness Ra _A of more than 200 nm and 2000 nm or less, and the smoothing portion B includes a region having an average surface roughness Ra _B of more than 5 nm and 200 nm or less. In the cross section of the hairline orthogonal direction and the plate | board thickness direction, the boundary of the said rough part A and the said smooth part B is the said zinc-type electricity in the range of 1 cm of observation width | variety along the said hairline orthogonal direction. Assuming that the height is one-third of the maximum height Ry minus the lowest point H ₀ from the highest point H ₁ of the plating layer and is on an imaginary straight line parallel to the hairline orthogonal direction, the roughening portion A The area ratio S _B / S _A is in the range of 0.6 to 10.0 when the area of S is referred to as S _A and the area of the smooth portion B is referred to as S _B. The average elevation difference between the rough portion A and the smooth portion B adjacent to the rough portion A is 0.3 µm to 3.0 µm.

Description

Zinc-based electroplated steel sheet

The present invention relates to a zinc-based electroplated steel sheet.

This application claims priority in 2010/12/12 based on Japanese Patent Application No. 2017-198465 for which it applied to Japan, and uses the content for it here.

People's visible items, including electrical appliances, building materials and automobiles, generally require designability. As a method of improving designability, the method of coating the surface of an article or attaching a film is common, but in recent years, application of the material which utilized the metal texture utilizing the nature-oriented taste is increasing. From the standpoint of utilizing the texture of the metal, since the coating and the resin coating damage the texture of the metal, stainless steel or aluminum, which is excellent in corrosion resistance even in an unpainted state, is used as the material of the article. Moreover, in order to improve the designability of a stainless steel material or an aluminum material, the appearance which gave fine linear irregularities called a hairline is given especially, although the circular arc unevenness | corrugation called a vibration or embossing etc. are given, Especially preferably, It is used a lot.

Hairline finish (HL finish) is one of the surface finishes of a stainless steel material, and is defined in JIS G4305: 2012 as "polishing and finishing so that continuous polishing eyes may be formed with an abrasive of an appropriate particle size".

However, since stainless steels and aluminum materials are expensive, inexpensive materials which replace these stainless steels and aluminum materials are desired. As one of such alternative materials, steel having the same high designability as that of stainless steel or aluminum and suitable corrosion resistance, and excellent in texture (metallic feeling) of metal having a hairline appearance suitable for use in electrical equipment or building materials, etc. There is.

As a technique of imparting proper corrosion resistance to steel materials, a technique of providing zinc plating or zinc alloy plating excellent in sacrificial corrosion resistance to steel materials is widely used. As a technique related to a steel material in which a hairline design is given to such zinc plating or zinc alloy plating (hereinafter referred to as zinc plating and zinc alloy plating collectively, also referred to as "zinc plating"), for example, orthogonal to the hairline direction. A technique for forming a light-transmitting adhesive layer and a light-transmitting film layer plating layer on the surface of the plating layer whose surface roughness Ra (arithmetic mean roughness) in the hairline orthogonal direction is 0.1 to 1.0 µm (see Patent Document 1 below). In addition, the roughness parameters Ra and PPI in the hairline direction and the hairline orthogonal direction formed on the surface layer of the Zn-Al-Mg-based hot-dip plating layer are in a specific range, and the transparent resin is formed on the surface of the Zn-Al-Mg-based hot-dip plating layer Resin whose surface roughness falls within a certain range with respect to a technique for forming a coating layer (see Patent Document 2 below) or a steel sheet transferred by rolling to Zn and Zn-based alloy plating by rolling. To suit technology (see the following Patent Document 3) are proposed.

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

However, in the technique of coating the organic resin on the steel sheet provided with the hairline design proposed in the above Patent Documents 1 to 3, the hairline design can be realized and a certain corrosion resistance can be expressed. There was a problem that the metallic feeling (metal gloss) was insufficient.

Here, as a method of forming a hairline, the steel plate rolling method which rolls the plated steel plate which wants to form a hairline with the rolling roll etc. which have predetermined roughness, and the plating grinding method which grinds the surface of the plated steel plate which wants to form a hairline There is this. The lack of metallic feeling (metal gloss) as described above was particularly noticeable in the plated steel sheet in which the hairline was formed by forming a hairline on the plated plate in the above-described steel sheet rolling method and then electroplating. The reason why the lack of metallic feeling is remarkable is not clear, but in the plated steel sheet produced by applying the hairline to the plated plate by the steel sheet rolling method, the incident light is caused by the unevenness of the plated crystal grains present on the outermost surface of the plated layer. It is considered to be because it is diffusely reflected at the surface of the plating layer. In addition, as described in Patent Literature 2, when the hairline is formed on the steel plate after plating by the steel sheet rolling method, the unevenness of the crystal grains of the plating is crushed by rolling, so that the metallic feeling becomes insufficient due to the diffused reflection of light. Although there is no problem, a problem arises in that adhesion to the resin film is insufficient because the plating surface is smoothed.

As a method for improving the glossiness, a method is known in which a predetermined organic substance additive is added to an electroplating liquid to refine the plating crystal grains (see, for example, Patent Document 4 above). However, when the crystal grain of plating is refined, there exists a problem that process adhesiveness with a resin film falls when the upper plating layer is resin-coated. Moreover, in the method of the said patent document 4, in order to obtain smooth plating, it is necessary to use an organic substance additive, and there existed a problem that the drag-out (waste liquid) process cost of a plating liquid increases.

Moreover, since the corrosion resistance of stainless steel itself is favorable by the oxide film which exists in the surface of stainless steel, the coating for improving corrosion resistance is unnecessary. That is, since the metal base itself can be used for the surface, a resin coating is not basically needed. On the other hand, when carrying out resin coating with respect to a stainless steel material, it aims to provide coloring or another texture. Therefore, in stainless steel, the loss of the metallic feeling which the present inventors discovered did not become a problem. This situation also applies to aluminum materials.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a predetermined corrosion resistance, have a hairline appearance, and have excellent metallic feel and workability while using an inexpensive steel material. To provide an associated electroplated steel sheet.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined the method for improving a metallic feeling, and considered that it is possible to improve a metallic feeling even when carrying out resin coating of the upper plating layer, if the diffuse reflection in the outermost surface of a plating layer can be suppressed. As a result of further studies of such an idea, the inventors have found that in order to suppress diffuse reflection, the inventors have found that smooth reflection can be suppressed by reducing unevenness of the crystal grains of plating. On the other hand, the part in which the unevenness | corrugation of the crystal grain of plating remains on the surface of a plating layer becomes a rough part, and work adhesiveness with a resin coating can be obtained. Therefore, by adjusting the ratio of such a rough part and a smooth part suitably, the knowledge that a metallic feeling and work adhesiveness were compatible was acquired.

Although zinc-based plating is excellent in sacrificial corrosion resistance, it is preferable to coat resin in order to ensure fingerprint-proof, workability, and corrosion resistance. Therefore, the present inventors examined separately about the plating steel material coated with resin. As a result, when the glossiness G60 (Gl) measured in the hairline direction is 70 to 400, and the glossiness G60 (Gc) measured in the hairline orthogonal direction is 0.3≤Gc / Gl≤0.7, I realized that I can feel a good metallic feeling, and if I get out of this range, the metallic feeling disappears. That is, the present inventors succeeded in quantifying the sense which a person feels "has a hairline appearance and is excellent in metallic feeling" for the first time.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examine the ratio of a rough part and a smooth part, under the various knowledge as mentioned above, even when an organic resin coating layer exists in the upper layer of a zinc-type electroplating layer, between metallic feeling and an organic resin coating layer and a zinc-type electroplating layer. The present invention was completed under the conditions for achieving the processing adhesiveness of.

The summary of this invention completed based on this knowledge is as follows.

[1] A steel sheet and a zinc-based electroplating layer having a hairline, which is located on at least one surface of the steel sheet, and which is a concave portion extending in a predetermined direction, are provided, wherein the zinc-based electroplating layer includes a rough portion A and a smooth portion. It consists of (B), The said roughening part _A contains the area | region whose average surface roughness Ra _A is more than 200 nm and 2000 nm or less, The said smooth part B has an average surface roughness Ra _{B more} than 5 nm and 200 nm. In the cross section of the hairline orthogonal direction which is orthogonal to the said predetermined direction, and the plate | board thickness direction, the boundary of the said rough part A and the said smooth part B is included, and is along the said hairline orthogonal direction. It is assumed that the height of 1/3 of the maximum height Ry minus the lowest point H ₀ from the highest point H ₁ of the zinc-based electroplating layer in the range of an observation width of 1 cm is on an imaginary straight line parallel to the hairline orthogonal direction. When each other When the area of the rough portion _A is S _A and the area of the smooth portion B is S _{B in the} same area unit, the area ratio S _B / S _A is in the range of 0.6 to 10.0, and the rough portion is The zinc-based electroplating steel plate whose average height difference between (A) and the said smooth part B adjacent to the said rough part A is 0.3 micrometer-3.0 micrometers.

[2] The total area of the region where the average surface roughness Ra _A in the rough portion _A is greater than 200 nm and 2000 nm or less is 85% or more relative to the area S _A of the rough portion _A , and the smooth portion is Zinc-based electroplating as described in [1] whose total area of the area whose said average surface roughness Ra _B in (B) is more than 5 nm and 200 nm or less is 65% or more with respect to area S _B of the said smooth part B. Grater.

[3] The zinc-based electroplated steel sheet according to [1] or [2], wherein the jaw portion A is formed in the hairline, and the average length along the stretching direction of the hairline is 1 cm or more.

[4] The zinc-based electroplated steel sheet according to [1] or [2], wherein the smooth portion B is formed in the hairline, and the average length along the stretching direction of the hairline is 1 cm or more.

[5] The hairline described in [3] or [4], wherein the hairline is present at an average of 3 / cm to 80 / cm in an arbitrary range of 1 cm in width along the hairline orthogonal direction. Zinc-based electroplated steel sheet.

[6] The zinc-based electroplating according to any one of [1] to [5], wherein a recess is formed at a position corresponding to the hairline in the zinc-based electroplating layer on the surface of the steel sheet. Grater.

[7] The zinc-based electroplated steel sheet according to any one of [1] to [6], wherein an average adhesion amount of the zinc-based electroplating layer is in a range of 5 g / m 2 to 40 g / m 2.

[8] The zinc-based electroplating layer may contain 5% by mass to 20% by mass of any one or more additional elements selected from the group consisting of Fe, Ni, and Co; The zinc-based electroplated steel sheet according to any one of [1] to [7], containing Zn as a balance and impurities.

[9] The zinc-based electroplated steel sheet according to [8], wherein the density of the plated particles having a particle size of 0.3 m or more in the jaw portion A is 10 ¹⁰ particles / m 2 or more.

Here, for example, when the zinc-based electroplating layer contains Fe as the additive element, the density of plated particles having a particle diameter of 0.5 µm or more in the roughening part A is 3 × 10 ¹⁰ / m 2 to 5 × 10 ¹⁴ pieces / m 2.

Alternatively, when the zinc-based electroplating layer contains Ni as the additive element, the density of the plated particles having a particle size of 0.3 μm or more in the rough portion A is 5 × 10 ¹⁰ / m 2 to 7 × 10 ¹⁴ pieces / M 2.

Alternatively, in the case where the zinc-based electroplating layer contains Co as the additive element, the density of the plated particles having a particle size of 0.6 µm or more in the rough portion A is 1 × 10 ¹⁰ / m 2 to 3 × 10 ¹⁴ / M 2.

[10] The zinc-based electroplated steel sheet according to any one of [1] to [7], wherein the zinc-based electroplating layer is made of Zn, and the hexagonal laminated plate aggregate crystal is included in the surface layer of the zinc-based electroplating layer.

[11] The zinc-based electroplated steel sheet according to any one of [1] to [10], further comprising a translucent organic resin coating layer on a surface of the zinc-based electroplating layer.

As described above, according to the present invention, it is possible to provide a zinc-based electroplated steel sheet that has predetermined corrosion resistance, has a hairline appearance, and is excellent in metallic feel and workability while using an inexpensive steel material.

1: A is explanatory drawing which shows typically an example of the structure of the zinc-based electroplating steel plate which concerns on embodiment of this invention, and is sectional drawing along the plate thickness direction.
1B is an explanatory diagram schematically showing an example of the structure of the zinc-based electroplated steel sheet according to the embodiment, and is a cross-sectional view along the plate thickness direction.
It is explanatory drawing for demonstrating an example of the zinc-based electroplating layer which concerns on this embodiment, and is an enlarged sectional view of the principal part along the plate | board thickness direction.
3 is a graph for explaining an example of a zinc-based electroplating layer according to the embodiment.
4 is a graph for explaining an example of a zinc-based electroplating layer according to the embodiment.
5 is a graph for explaining an example of a zinc-based electroplating layer according to the embodiment.
It is explanatory drawing for demonstrating another example of the zinc-based electroplating layer which concerns on this embodiment, and is an enlarged sectional view of the principal part along the plate | board thickness direction.
7A is an explanatory diagram schematically showing another example of the structure of the zinc-based electroplated steel sheet according to the embodiment, and is a cross-sectional view along the plate thickness direction.
7B is an explanatory diagram schematically showing another example of the structure of the zinc-based electroplated steel sheet according to the embodiment, and is a cross-sectional view along the plate thickness direction.
FIG. 8A is an example of the microscope image at the time of electron microscope observation of the surface of the zinc type electroplating layer which the zinc type electroplating steel plate concerning this embodiment has.
8B is an example of the microscope image at the time of the electron microscope observation of the surface of the zinc-based electroplating layer which the zinc-based electroplating steel plate which concerns on this embodiment has.
FIG. 9A is an example of a microscope image when the surface of the zinc-based electroplating layer of the zinc-based electroplated steel sheet according to the embodiment is observed under an electron microscope, and (B) and (C) are partial enlarged views thereof. FIG. to be.
10 is a graph showing a measurement example of a surface height of a zinc-based electroplated layer of the zinc-based electroplated steel sheet according to the embodiment.
FIG. 11A is an example of a microscope image when the surface of the zinc-based electroplating layer of a general zinc-based electroplated steel sheet is observed with an electron microscope, and (B) is a partially enlarged view thereof.
FIG. 12 is a cross-sectional view for explaining an imaginary line forming a boundary between a grandfather and a smooth portion, (A) shows a case of the form shown in FIG. 2, and (B) shows a case of the form shown in FIG. Illustrated.

EMBODIMENT OF THE INVENTION Preferred embodiment of this invention is described in detail, referring an accompanying drawing below. In addition, in this specification and drawing, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol about the component which has substantially the same functional structure.

(About the whole composition of the zinc-based electroplated steel sheet)

Hereinafter, the whole structure of the zinc-based electroplating steel plate which concerns on embodiment of this invention is demonstrated in detail, referring FIG. 1A and FIG. 1B first. 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.

As shown schematically in FIG. 1A, the zinc-based electroplated steel sheet 1 according to the present embodiment includes a steel sheet 11 serving as a base material and a zinc-based electroplated layer disposed on either surface of the steel sheet 11 ( Have at least 13). In addition, as shown in FIG. 1B, the zinc-based electroplated steel sheet 1 according to the present embodiment further has an organic resin coating layer 15 having light transparency on the surface side of the zinc-based electroplated layer 13. desirable.

<About mention>

The steel plate 11 which is a base material of the zinc-based electroplating steel sheet which concerns on this embodiment is not specifically limited, According to the mechanical strength (for example, tensile strength etc.) calculated | required by a zinc-based electroplating steel sheet, etc. Steels (mild steel, ordinary steel, high tensile strength steel, etc.) can be used suitably.

<About zinc-based electroplating layer>

The zinc-based electroplating layer 13 is formed on one surface of the steel sheet 11 as described above. In the zinc-based electroplating layer 13 according to the present embodiment, as shown schematically in FIG. 1A, the concave portion 101 forming a hairline that is elongated in a predetermined direction (in the case of FIG. 1A, in the vertical direction of the paper). And the non-hairline section 103. In the zinc-based electroplating layer 13 according to the present embodiment, in the concave portion 101 that forms the hairline, a rough portion described in detail below is formed, and further, in the non-hairline portion 103, The smoothing part demonstrated in detail may be formed. Or in the zinc-based electroplating layer 13 which concerns on this embodiment, the smooth part demonstrated in detail below is formed in the recessed part 101 which forms a hairline, and the non-hairline part 103, The rough part demonstrated in detail below may be formed. Also in any case, it is preferable that the average length along the extending direction of a hairline is 1 cm or more.

As a depth of a hairline, what is 5% or more and 50% or less of the average plating thickness of the zinc-based electroplating layer 13 is illustrated. As a more specific hairline depth, what exists in the range of 0.2 micrometer or more and 2.5 micrometers or less is illustrated. In addition, although the cross-sectional shape of the hairline in the cross section orthogonal to the extending | stretching direction of a hairline is V shape mainly, you may also include a U shape.

In the following description, the "direction in which the hairline is drawn" is abbreviated as "hairline direction", and the "direction orthogonal to the drawing direction of the hairline" is abbreviated as "hairline orthogonal direction". In addition, the said rough part and the smooth part are demonstrated in detail again below.

[Types and Compositions of Zinc-Based Electroplating Layers]

As the zinc-based electroplating layer 13 according to the present embodiment, electro-galvanization or electro-zinc alloy plating (hereinafter, collectively referred to as "zinc-based electroplating") is used.

First, with respect to the plating metal, in the plating other than zinc-based plating, sacrificial corrosion resistance is inferior, and therefore, it is not suitable for the use in which the cut end surface is inevitably exposed in use. In addition, since the sacrificial anticorrosion performance will be lost when the zinc concentration in a plating film becomes low too much, it is preferable that zinc alloy plating contains 65 mass% or more of zinc with respect to the total mass of a plating film.

Specifically, Zn content in zinc plating is preferably 65 mass% or more, more preferably 70 mass% or more, and particularly preferably 80 based on the total mass of the plating film. It is mass% or more. In addition, the upper limit of Zn content in zinc plating is 100 mass%.

As the plating method, in addition to electroplating, there are a hot dip plating method, a thermal spraying method, a vapor deposition plating method, and the like. However, in the hot-dip plating method, since the appearance quality deteriorates due to solidification patterns such as sequins and dross unavoidably mixed in the plating layer, they are not suitable. Moreover, in the thermal spraying method, the uniformity of external appearance cannot be ensured by the space | gap inside a plating film, and it is unsuitable. In addition, the vapor deposition method is unsuitable because the deposition rate is low and the productivity is insufficient. Therefore, in the zinc-based electroplated steel sheet 1 according to the present embodiment, electroplating is used to perform zinc-based plating on the steel surface.

Here, the electro-zinc alloy plating used as the zinc-based electroplating layer 13 according to the present embodiment is an element group consisting of Co, Cr, Cu, Fe, Ni, P, Sn, Mn, Mo, V, W, and Zr. It is preferable to contain at least any additional element selected, and Zn. In particular, it is preferable that electro zinc alloy plating contains 5 mass% or more and 20 mass% or less of at least any additional element selected from the element group which consists of Fe, Ni, and Co. By the electro zinc alloy plating containing at least any additional element of Fe, Ni, and Co within the said total content, it becomes possible to implement | achieve more excellent corrosion resistance (white-blue blueness / barrier resistance).

In addition, electro zinc plating and electro zinc alloy plating may contain the impurity as remainder. Here, the impurity is not consciously added as a zinc-based electroplating component, but is mixed in the raw material or mixed in the manufacturing process, and 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. In the case of performing electrogalvanization, Co, Cr, Cu, Fe, Ni, P, Sn, Mn, Mo, V, W, Zr is impurity depending on the type of electroplating steel produced in the same manufacturing facility. It may be mixed as. In this embodiment, even if an impurity exists about 1 mass% in total with respect to the mass of all plating, the effect obtained by plating is not impaired.

In addition, intentionally added Fe, Ni, Co, and Fe, Ni, Co mixed as impurities can be determined by the concentration in the zinc-based electroplating layer 13. That is, since the lower limit of the total content of Fe, Ni, and Co in the case of intentionally adding is 5% by mass, it can be discriminated as an impurity if the total content is less than 5% by mass.

The composition of the zinc-based electroplating layer as described above can be analyzed, for example, by the following method. That is, after removing the organic resin coating layer with a release agent such as a solvent that does not corrode plating or a remover (for example, Neo River S-701: manufactured by Sansai Chemical Co., Ltd.), the zinc-based electroplating layer may be replaced with hydrochloric acid containing an inhibitor. Dissolve. The dissolved solution is then analyzed by an ICP (Inductively Coupled Plasma) emission spectrophotometer. As the inhibitor, NO.700AS manufactured by Asahi Chemical Industries, Ltd. can be used.

[Average Amount of Deposit of Zinc-Based Electroplating Layer 13]

It is preferable that the average adhesion amount of the zinc-based electroplating layer 13 which concerns on this embodiment is 5 g / m <2> or more and 40 g / m <2> or less. When the average adhesion amount of the zinc-based electroplating layer 13 is less than 5 g / m 2, there is a possibility that the base iron (that is, the steel plate 11) is exposed when the hairline is applied. On the other hand, when the average adhesion amount of the zinc-based electroplating layer 13 exceeds 40 g / m 2, the hairline formed by grinding or rolling on the steel sheet 11 is less noticeable by the zinc-based electroplating layer 13. As there is possibility of quality, it is not desirable. The lower limit of the average adhesion amount of the zinc-based electroplating layer 13 is more preferably 7 g / m 2, still more preferably 10 g / m 2. Moreover, the upper limit of the average adhesion amount of the zinc-based electroplating layer 13 becomes like this. More preferably, it is 35 g / m <2> or less, More preferably, it is 30 g / m <2>.

<About organic resin coating layer>

As shown schematically in FIG. 1B, the surface of the zinc-based electroplating layer 13 provided with the hairline design as described above is preferably coated with a transparent resin (in other words, a resin having transparency). That is, it is preferable that the organic resin coating layer 15 is provided in the surface side of the zinc-based electroplating layer 13 which concerns on this embodiment. Here, in this embodiment, the "resin has light transmittance" refers to visually observing the zinc-based electroplating layer 13 through the organic resin coating layer 15 formed on the surface of the zinc-based electroplating layer 13. It means you can.

[Components of Organic Resin Coating Layer]

It is preferable that resin used for formation of the organic resin coating layer 15 is equipped with sufficient transparency, chemical-resistance, corrosion resistance, workability, scratch resistance, etc. Examples of such resins include polyester resins, epoxy resins, urethane resins, polyester resins, phenolic resins, polyether sulfone resins, melamine alkyd resins, acrylic resins, polyamide resins, and polyimides. Resins, silicone resins, polyvinyl acetate resins, polyolefin resins, polystyrene resins, vinyl chloride resins, vinyl acetate resins, and the like.

Further, as a means for improving the adhesion between the organic resin coating layer 15 and the zinc-based electroplating layer 13, a plating made of the steel plate 11 and the zinc-based electroplating layer 13 within a range that does not impair the appearance. The steel material may be subjected to an inorganic treatment, an organic inorganic composite treatment, a surface modification treatment, or the like. Here, "damaging the appearance" means reducing transparency, generating gloss unevenness, generating strange rough convexity, or reducing metallic feeling. As a process which improves adhesiveness, a Zr oxide process, a Zn oxide process, a silane coupling agent process, a weak acid immersion process, a weak alkali immersion process, etc. are mentioned, for example.

In addition, in order to add desired performance to the organic resin coating layer 15, various additives are contained in the organic resin coating layer 15 within a range that does not impair transparency and appearance and does not deviate from the range defined by the present invention. You can also do it. As performance added to the organic resin coating layer 15, corrosion resistance, sliding mobility, damage resistance, electroconductivity, color tone, etc. are mentioned, for example. For example, if it is corrosion resistant, it may contain a rust preventive agent, an inhibitor, etc., if it is sliding mobility, or damage resistance, it may contain wax, a beads, etc., if it is electroconductive, if it is electroconductive, it may contain a conductive agent, etc., if it is a color tone, a pigment, dye, etc. You may contain the well-known coloring agent of.

In addition, when it contains well-known coloring agents, such as a pigment and dye, with respect to the organic resin coating layer 15 which concerns on this embodiment, it is preferable to contain a coloring agent so that a hairline can be visually recognized.

[About thickness of organic resin coating layer]

It is preferable that the average thickness of the organic resin coating layer 15 which concerns on this embodiment is 10 micrometers or less. When the average thickness of the organic resin coating layer 15 exceeds 10 micrometers, since the distance which light passes through the inside of the organic resin coating layer 15 becomes long, the reflected light will decrease and the glossiness will fall high. Moreover, the deformation | transformation of resin with a process makes it easy to produce the shift of 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. FIG. For the above reason, it is preferable that it is 10 micrometers or less, and, as for the average thickness of the organic resin coating layer 15, it is more preferable that it is 8 micrometers or less.

On the other hand, from the viewpoint of corrosion resistance, the thickness of the thinnest part (that is, the minimum value of the thickness of the organic resin coating layer 15) is 0.1 µm or more from the cross section of the organic resin coating layer 15, and the organic resin coating layer 15 It is preferable that average thickness is 1.0 micrometer or more. Here, "the thinnest part" means the minimum value of the film thickness which cut out the length of 5 mm in arbitrary positions in the direction orthogonal to a hairline, and made a cross-sectional sample, measured 20 points | pieces at 100 micrometer space | interval, "Average thickness" means the average of 20 points. It is more preferable that the thickness of the thinnest part of the organic resin coating layer 15 is 0.5 micrometer or more, and the average thickness of the organic resin coating layer 15 is 3.0 micrometers or more.

In the above, the whole structure of the zinc-based electroplating steel plate 1 which concerns on this embodiment was demonstrated in detail. In addition, although FIG. 1A and FIG. 1B show the case where the zinc type electroplating layer 13 and the organic resin coating layer 15 are formed in one surface of the steel plate 11, the steel plate 11 mutually forms front and back. The zinc-based electroplating layer 13 and the organic resin coating layer 15 may be formed on both surfaces.

(About surface shape of 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 FIGS. 2 to 6. 2 is an explanatory diagram for explaining an example of a zinc-based electroplating layer according to the present embodiment. 3 to 5 are graphs for explaining an example of the zinc-based electroplating layer according to the present embodiment. 6 is an explanatory diagram for explaining another example of the zinc-based electroplating layer according to the present embodiment.

As mentioned above, the zinc-type electroplating layer 13 which concerns on this embodiment has the recessed part 101 which forms a hairline, and the non-hairline part 103 in the surface layer part. In addition, when focusing on the surface shape of the micro zinc-type electroplating layer 13 different from a hairline, the zinc-based electroplating layer 13 which concerns on this embodiment contains the area whose average surface roughness Ra is more than 200 nm and 2000 nm or less. It has a rough part 111 and the smooth part 113 containing the area | region whose average surface roughness Ra is more than 5 nm and 200 nm or less.

In the zinc-based electroplating layer 13 according to the present embodiment, the above-described rough portions 111 may be formed in the hairline, and the above smooth portions 113 may be formed in the hairline. That is, even if the above-mentioned rough part 111 is formed in the recessed part 101 which forms a hairline, and the said smooth part 113 is formed in the non-hairline part 103, even if it has an aspect. Or the above smooth portion 113 is formed in the concave portion 101 forming the hairline, and the above-described rough portion 111 is formed in the non-hairline portion 103. You may be.

Here, about the area ratio of the rough part and the smooth part in this embodiment, although it is also possible to obtain | require the actual surface state by observing with SEM etc. and measuring each area ratio, in this invention, roughness with a laser microscope is mentioned later. The profile was measured, the roughness equivalent part and the smooth part correspondence part were set by the boundary line by the virtual straight line based on it, and the area ratio was used.

The boundary line between the rough part 111 and the smooth part 113 in this embodiment was defined as follows.

First, as shown in FIG. 2 and FIG. 12A, in the zinc-based electroplating layer 13 according to the present embodiment, the jaw portion 111 is formed in the concave portion 101 forming a hairline. In addition, attention is paid to the case where the smooth portion 113 is mainly formed in the non-hairline portion 103. In this case, the magnification is achieved 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 (that is, a laser microscope having a display resolution in the height direction and the width direction of more than 1 nm). The surface height of the zinc-based electroplating layer 13 in the range of 1 cm x 1 cm by planar view at 500 times is measured. When the observation visual field of a laser microscope is less than 1 cm, you may observe multiple visual fields, and may connect these and measure the surface height.

Then, along the hairline direction in 100㎛ interval, and the hair line perpendicular direction and also plot the height of the surface of the cross-section ((A) in Fig. 12) in the plate thickness direction, and the lowest point (H ₀ of the height of its cross-section, within ) And the highest point H ₁ are specified, respectively. "Smooth portions 113", has a region which is defined by a set of points not less than the height _{(H 1 -H 0) × 1} /3 from the lowest point (H _0). On the other hand, "demodulator 111 'has a region which is defined by a set of the lowest point (H ₀₎ is the height from the (H ₀ -H ₁₎ × less than 1/3 points. That is, the boundary between the rough part 111 and the smooth part 113 is the hairline orthogonal direction and the observation width 1 along the hairline orthogonal direction in each of the cross sections (FIG. 12 (A)) of the plate thickness direction. ㎝ height of the zinc-based one-third of the maximum height Ry obtained by subtracting the low point H ₀ H ₁ from the highest point of the electroplating layer 13 in the range of addition is present on the virtual straight line BL parallels to the hair line perpendicular to the direction .

The roughening part 111 is corresponded to the part which is not influenced by the process of grinding, rolling, etc. after formation of the zinc-type electroplating layer 13. As shown in FIG. Therefore, when the surface of the zinc-based electroplating layer 13 is observed under a microscope, the crystal grains having a height can be confirmed in the jaw portion 111. About the height regulation of a crystal grain, it is as above-mentioned.

In addition, the shape of the crystal grain when the rough part 111 is planarly viewed is a polygonal structure, and in the case of pure zinc which does not contain an additional element in the zinc-based electroplating layer 13, the crystal shape resulting from the dense hexagonal hexagon of zinc (Hexagonal laminated plate assembly determination) is taken.

In the case where the zinc-based electroplating layer 13 contains an additive element, the size of the crystal grains varies depending on the additive element included, plating conditions (current density, relative flow rates of the plating liquid and the steel sheet), and the like.

The average particle diameter D _ave indicating the size of crystal grains (plated particles) is obtained by the following method.

First, the surface of the zinc-based electroplating layer 13 is observed by SEM. Although the visual field magnification at that time exists in the range of 1000-10000 times, when plated particle is not able to be confirmed even at the maximum magnification of 10000 times, it counts as the number zero. Subsequently, the planar area S per plated particle is obtained from the outline of the plated particle. And the circle which has the same planar area as the planar area is assumed, and the diameter is calculated | required as said representative diameter D by following formula (1). And the average particle diameter D _ave is calculated | required by arbitrarily selecting ten plating particles in an observation visual field, and obtaining the average value of the representative diameter D of those ten plating particles.

D = 2 × (S / π) ^0.5 . Formula (1)

Here, D is a representative diameter in plan view of the plated particles and the unit is µm. In addition, S is a circular equivalent area in plan view of plated particles, and its unit is µm ² .

In addition, the density of a crystal grain is calculated | required by the following method.

First, as described above, the surface of the zinc-based electroplating layer 13 is observed by SEM, and the density of the plated particles is determined by counting how much the plated particles having a particle size threshold value or more is within a range of 10 μm × 10 μm. The grain size threshold is different for each alloy, and Zn-Ni is 0.1 µm to 2.5 µm, Zn-Fe is 0.3 µm to 3.0 µm, and Zn-Co is 0.4 µm to 8.0 µm.

In addition, when plated particle | grains cannot be confirmed even if the magnification of SEM is made into the largest magnification (10000 times), it counts as the number zero.

In the case where the zinc-based electroplating layer 13 is Zn-Fe, the average particle diameter D _ave of the crystal grains (plated particles) in the rough portion 111 is in a range of 0.5 µm to 2.2 µm. In addition, the density of the crystal grain in the rough part 111 exists in the range of 3 * 10 <^10> / m <2> -5 * 10 <^14> / m <2>. As an example of the measured value, when the zinc-based electroplating layer 13 was Zn-Fe, the crystal grains in the rough portion 111 had an average particle diameter D _ave of 1.78 μm and a density of 6.5 × 10 ¹³ particles / m 2. .

In addition, when the zinc-based electroplating layer 13 is Zn-Co, the average particle diameter D _ave of the crystal grain (plating particle) in the roughening part 111 will be in the range of 0.6 micrometer-6.0 micrometers. In addition, the density of the crystal grain in the rough part 111 exists in the range of 1 * 10 <^10> / m <2> -3x10 <^14> / m <2>. As an example of the measured value, when the zinc-based electroplating layer 13 was Zn-Co, the crystal grains in the rough portion 111 had an average particle diameter D _ave of 5.13 μm and a density of 2.2 × 10 ¹² particles / m 2.

In addition, when the zinc-based electroplating layer 13 is Zn-Ni, the average particle diameter D _ave of the crystal grain (plating particle) in the roughening part 111 will be in the range of 0.3 micrometer-2.0 micrometers. In addition, the density of the crystal grain in the rough part 111 exists in the range of 5 * 10 <^10> piece / m <2> -7 * 10 <^14> piece / m <2>. As an example of the measured value, when the zinc-based electroplating layer 13 was Zn-Ni, the crystal grains in the rough portion 111 had an average particle diameter D _ave of 0.6 µm and a density of 4.4 × 10 ¹² particles / m 2.

In summary, in the case where any one or more elements selected from the group consisting of Fe, Ni, and Co are included as addition elements in the zinc-based electroplating layer 13, the particle diameter of the roughening 111 is 0.3 µm or more. The density of the plating particles is 10 ¹⁰ pieces / m 2 or more.

6 and 12 (B), in the zinc-based electroplating layer 13 according to the present embodiment, the smooth portion 113 is formed in the concave portion 101 forming the hairline. In addition, attention is paid to the case where the rough portion 111 is mainly formed in the non-hairline portion 103. In this case, the magnification is achieved 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 (that is, a laser microscope having a display resolution in the height direction and the width direction of more than 1 nm). The surface height of the zinc-based electroplating layer 13 in the range of 1 cm x 1 cm is measured by planar view at 500 times. When the observation visual field of a laser microscope is less than 1 cm, you may observe multiple visual fields, and may connect these and measure the surface height.

Next, the surface height of the cross section in the hairline orthogonal direction and the sheet thickness direction is plotted along the hairline direction at intervals of 100 μm, and the lowest point H ₀ and the highest point H ₁ of the height in the cross section are plotted. Each is specified. "Grandfather 111" is the area defined by the set of points greater than the height from the lowest point _{(H 0) (H 1 -H} 0) × 1/3. On the other hand, "the smoothing part 113" is a region defined by a set of (H ₁ -H ₀₎ × less than 1/3 the height of the point from the lowest point (H _0). And the boundary between these rough part 111 and the smooth part 113 is a zinc system in the range of 1 cm of observation width along a hairline orthogonal direction in each cross section of a hairline orthogonal direction and a plate thickness direction. the height of the maximum height Ry obtained by subtracting 1/3 from the highest point to the lowest point H ₀ H ₁ of the electroplating layer is also present on the imaginary straight lines BL forming a parallel to the hair line perpendicular direction.

In the zinc-based electroplating layer 13 according to the present embodiment, the above rough portion 111 corresponds to the portion where the unevenness of the crystal grains of the plating exists, and the smooth portion 113 as described above is the rough portion ( 111) corresponds to the portion where the unevenness of the plating crystal grains is smaller. In the zinc-based electroplating layer 13 according to the present embodiment, an appropriate ratio is provided between the rough portion 111 in which the unevenness of the crystal grains of the plating exists and the smooth portion 113 in which the unevenness of the crystal grains of the plating is smaller than the rough portion 111. It exists as. Thereby, while the smooth part 113 realizes the improvement of metallic feeling, in the rough part 111, it is preferable to provide the process adhesiveness with the organic resin coating layer 15 provided in the upper layer of the zinc-based electroplating layer 13. To realize.

Hereinafter, the various conditions required for the zinc-based electroplating layer 13 in order to achieve both metallic feeling and workability even when the organic resin coating layer 15 is present on the upper layer of the zinc-based electroplating layer 13 are described in detail. Explain. In addition, below, the case where the rough part 111 is formed in the recessed part 101 which comprises a hairline, and the smooth part 113 is formed in the non-hairline part 103 is given, and demonstrates as an example. Shall be.

[Difference between average surface height of grandfather and average surface height of smooth part]

Since the zinc-based electroplating layer 13 which concerns on this embodiment has both the rough part 111 and the smooth part 113 as mentioned above, as shown typically in FIG. 2, rough part adjacent to each other For each of the 111 and the smooth portions 113, the average surface height of the rough portion 111 and the average surface height of the smooth portions 113 can be considered. At this time, in the zinc-based electroplating layer 13 according to the present embodiment, the average height difference between the rough portion 111 and the smooth portion 113 adjacent to the rough portion 111 (the rough portion 111 and the rough portion 111). The difference of the average surface height of the adjacent smooth part 113) is 0.3 micrometer-3.0 micrometers. That is, in the zinc-based electroplating layer 13 according to the present embodiment, approximately all of the recesses 101 forming the hairline are rough portions 111, and approximately all of the non-hairline portions 103 are smooth portions ( 113), the average height difference between these recessed portions 101 and non-hairline portions 103 is in the range of 0.3 µm to 3.0 µm.

For example, in the example shown in Figure 2, the grandfather A ₂ formed in the concave portion 101 to form a hairline, a smoothing unit B ₃ formed in the non-hair line portion 103 and adjacent to each other, grandfather a ₂ and the average height difference of the smoothing unit ₃ B, it can be identified by known measurement methods. At this time, the height difference (Δh in FIG. 2) between the average surface height of the smooth portion B _{3 and} the average surface height of the rough portion A ₂ is in a range of 0.3 μm to 3.0 μm. The same relationship is also established between the rough portion A ₂ and the smooth portion B ₂ , between the rough portion A ₁ and the smooth portion B ₂ , or between the rough portion A ₁ and the smooth portion B ₁ .

When the average height difference of the smooth part 113 and the rough part 111 which adjoin each other is less than 0.3 micrometer, a hairline will become inconspicuous and it will be useless to give the zinc-based electroplating layer 13 the hairline process. On the other hand, when the average height difference of the smooth part 113 and the rough part 111 which adjoin each other exceeds 3.0 micrometers, a hairline will become too rough and it will not become a clean hairline, and the designability as a hairline will be impaired. The lower limit value of the average height difference between the smooth part 113 and the rough part 111 which adjoin each other becomes like this. Preferably it is 0.8 micrometer, More preferably, it is 1.0 micrometer. Moreover, the upper limit of the average height difference of the smooth part 113 and the rough part 111 which adjoin each other becomes like this. Preferably it is 2.6 micrometers, More preferably, it is 2.2 micrometers.

In addition, the average height difference of the rough part 111 and the smooth part 113 can be measured by measuring the surface of the zinc-based electroplating layer 13 with a laser microscope, for example. At this time, in each of the several places of the zinc-based electroplating layer 13, the height difference to the smooth part 113 is measured using the rough part 111 as a reference height. The average height difference obtained by the average of the plurality of height differences Δh is further averaged by dividing by the number of measurement points, thereby making it the average height difference between the rough portion 111 and the smooth portion 113.

[Area ratio of the area of the grandfather to the area of the smooth part]

In addition, in the zinc-based electroplating layer 13 according to the present embodiment, the area (total planar area of the area corresponding to the rough part 111) of the rough part 111 is referred to as S _A , and the area (of the smooth part 113) ( when the total plan view) of the area corresponding to the smooth portions 113 have as S _B, a ratio S _B / S _a of the same area as each other units it is in the range of 0.6 to 10.0. At this time, for the In in the example, the range shown in Figure 2, the total of the two-dimensional and demodulator area of A ₂ in the grandfather A _1, and an area S _A of the demodulator 111 in the range shown in Figure 2, smooth portion, the total area of the area of the smooth portions B _2, B ₃ of area and the smooth portion of the B _1, is a surface area S _B of the smoothing section 113 in the range shown in FIG. In addition, as shown in FIG. 8B, a planar area is an area when it sees on a plane, ie, an area when it sees as an image when observed with an electric microscope.

Hereinafter, the reason why the area ratio S _B / S _{A as described above} is important will be described in detail with reference to FIGS. 3 to 5.

3 shows a commercially available gloss meter when the surface roughness Ra (arithmetic mean roughness Ra specified in JIS B 0601) of the smoothing part 113 is changed after fixing the value of the area ratio S _B / S _A to 2.0. It shows the result of measuring 60 degree glossiness G60 using. In FIG. 3, the horizontal axis is the surface roughness Ra of the smooth part 113, and the vertical axis is the measurement result of 60 degree gloss. In addition, in FIG. 3, the measurement result in each of the extending direction (henceforth hairline direction) of a hairline, and the direction orthogonal to a hairline (henceforth hairline orthogonal direction) is shown.

As is apparent from FIG. 3, in the measurement results of both the hairline direction and the hairline orthogonal direction, the greater the surface roughness Ra of the smooth portion 113 (in other words, the more smoothness is lost from the smooth portion 113). , The 60-degree gloss value decreases and the metallic feeling decreases. From these results, it can be seen that by providing the smooth portion 113, it is possible to suppress diffuse reflection of light reaching the surface of the zinc-based electroplating layer 13 and to improve glossiness.

4 shows a 60 degree gloss (G60) using a commercially available gloss meter when the surface roughness Ra of the smooth portion 113 is adjusted to 20 ± 5 nm and the area ratio S _B / S _A is changed. It shows the result of measuring. In FIG. 4, the horizontal axis is the area ratio S _B / S _A , and the vertical axis is the measurement result of 60 degree gloss.

As is apparent from FIG. 4, when the area ratio S _B / S _{A is set} to 0.6 or more, it is weak in the hairline direction as compared with the case where the smooth portion 113 is not provided (area ratio S _B / S _A = 0). The glossiness of five times or more can be realized, and the glossiness of about three times or more can also be realized in the hairline orthogonal direction.

On the other hand, the result of having provided the organic resin coating layer 15 in the surface of the same sample used for the measurement of FIG. 4, and evaluated the processing adhesiveness is FIG. In addition, evaluation of work adhesiveness was performed similarly to the method demonstrated in the following Example, and evaluated in five steps from the grade 5 which means the outstanding work adhesiveness to the grade 1 which means that the work adhesiveness is inferior. As apparent from FIG. 5, in the sample having an area ratio S _B / S _A of 10 or less, the work adhesiveness was evaluated as a rating of 5, whereas in the sample in which the area ratio S _B / S _A exceeded 10, the work adhesiveness rapidly decreased. It became.

In addition, the same measurement as FIG. 4 and FIG. 5 was implemented, changing the surface roughness Ra of the smooth part 113 in the range of 5 nm-200 nm. Also in this case, by setting the area ratio S _B / S _A to 0.6 or more, a significantly superior gloss can be realized than when the smooth portion 113 is not provided (when the area ratio S _B / S _A = 0). If the area ratio S _B / S _a is larger than 10, the processing adhesion was drastically reduced.

From the above results, in the zinc electroplating layer 13 according to this embodiment, it became clear that it is important that the range of the area ratio S _B / S _A 0.6 to 10.0. In the zinc-based electroplating layer 13 according to the present embodiment, the lower limit of the area ratio S _B / S _A is preferably 1.5, and more preferably 2.5. In addition, the upper limit of the area ratio S _B / S _A is preferably 8.0, and more preferably 6.5.

Here, the area (total planar area of the area corresponding to the rough part 111) S _A of the rough part 111 and the area (total planar area of the area corresponding to the smooth part 113) S _B of the smooth part 113 are the heights. It can measure by binarizing the height data measured with the laser microscope whose display resolution of a direction is 1 nm or more, and the display resolution of the width direction is 1 nm or more, and performing the well-known image process with respect to the obtained binary data. .

As described above, the conditions for the average height difference between the rough portion 111 and the smooth portion 113 and the area ratio S _B / S _A between the rough portion 111 and the smooth portion 113 are as shown in FIG. 2. As well as the case where the same jaw 111 is formed in the recessed part 101 which comprises a hairline, and the smooth part 113 is formed in the non-hairline part 103, as shown typically in FIG. Similarly, it is confirmed that the smooth portion 113 is formed in the concave portion 101 constituting the hairline, and the same applies to the case where the rough portion 111 is formed in the non-hairline portion 103.

[Surface Roughness in Roughness]

As mentioned above, in the zinc-based electroplating layer 13 according to the present embodiment, the coarse portion 111 is present at an appropriate ratio, whereby the organic resin coating layer 15 is formed on the upper layer of the zinc-based electroplating layer 13. It secures the processing adhesiveness when it is prepared. Here, in order to ensure processing adhesiveness by the roughening part 111, it is preferable that the roughening part 111 has the area of the suitable area which has an appropriate surface roughness, and it is preferable that the contact area with the organic resin coating layer 15 increases. .

Therefore, in the zinc-based electroplating layer 13 which concerns on this embodiment, the rough part 111 is measured using the laser microscope whose display resolution of a height direction is 1 nm or more, and the display resolution of the width direction is 1 nm or more. When considering, the area whose surface roughness Ra _A is more than 200 nm and 2000 nm or less, and it is preferable that the total area of such an area | region becomes 85% or more with respect to area S _A of the rough part 111.

Since the surface roughness Ra _A of the part which contacts the organic resin coating layer 15 becomes more than 200 nm and 2000 nm or less, the contact state with the organic resin coating layer 15 which can implement | achieve the outstanding work adhesiveness can be realized more reliably. have. In the case where the sum of the areas of the same region, with respect to the area S _A of the demodulator 111, which is less than 85%, that in the zinc-based electroplated steel sheet (1) according to one embodiment of the invention, realizing the excellent working adhesion It may become difficult. Therefore, in the zinc-based electroplated steel sheet 1 according to the present embodiment, the ratio of the total area to the area S _A of the jaw portion 111 is preferably 85% or more.

In addition, the ratio of the total area of the area | region where surface roughness Ra _A becomes more than 200 nm and 2000 nm or less with respect to area S _A of the rough part 111 is so good that it is high, Preferably it is 90% or more, More preferably, Is 95% or more. In addition, the upper limit of the ratio of the total area to the area S _A of the demodulator 111 is not necessarily otherwise specified, it may be 100%.

[Surface roughness in the smooth part]

In addition, as mentioned above, in the zinc type electroplating layer 13 which concerns on this embodiment, since the smooth part 113 exists in an appropriate ratio, the zinc-based electroplating steel sheet 1 which concerns on this embodiment is carried out. I realize a metallic feeling. Here, in order to realize the improvement effect of the metallic feeling by the smooth part 113, as illustrated in FIG. 4, it is preferable that the smooth part 113 has the area | region of the suitable area which has an appropriate surface roughness.

Therefore, in the zinc-based electroplating layer 13 according to the present embodiment, the smooth portion 113 is formed by using a laser microscope whose display resolution in the height direction is 1 nm or more and the display resolution in the width direction is 1 nm or more. When measuring, considering the area | region where surface roughness Ra _B is more than 5 nm and 200 nm or less, it is preferable that the total area of such an area | region becomes 65% or more with respect to area S _B of the smooth part 113.

When the surface roughness Ra _B of the smooth part 113 becomes more than 5 nm and 200 nm or less, the outstanding glossiness can be implement | achieved more reliably. In the case where the sum of the areas of the same region, with respect to the area S _B of the smoothing part 113, which is less than 65%, that in the zinc-based electroplated steel sheet 1 according to the present embodiment, realizing a feeling excellent metallic It may become difficult. Therefore, in the zinc-based electroplated steel sheet 1 according to the present embodiment, the ratio of the total area to the area S _B of the smooth portion 113 is made 65% or more.

Further, the ratio of the total area to the area S _B of the smoothing part 113 is, well the higher, preferably at least 70%, more preferably at least 75%. In addition, the upper limit of the ratio of the total area to the area S _B of the smoothing section 113 is not necessarily otherwise specified, it may be 100%.

The total area as described above is obtained 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, to determine the surface roughness Ra of the smooth portion 113 or the rough portion 111. It can measure by 1 micrometer space | interval along the same direction as a hairline, and can obtain | require by following formula (2) and formula (3). In this case, if the measurement length of Ra is too short, the local surface roughness is measured. Therefore, the measurement length is set to 50 µm or more. When the observation visual field of a laser microscope is less than 50 micrometers, Ra may be calculated | required by observing multiple visual fields and connecting multiple visual fields.

Grandfather total area: S _A x (the number of times Ra became 200 nm or more and less than 2000 nm / the total number of measurements). Formula (2)

Smooth part total area: S _B x (number of times Ra becomes 20 nm or less and 200 nm / total number of measurements). Formula (3)

[Frequency of Hairline Formation]

In addition, in the zinc-based electroplating layer 13 according to the present embodiment, the concave portion 101 including the above-described rough portion 111 or the smooth portion 113 has an arbitrary width of 1 cm along the hairline orthogonal direction. It is preferable to exist at the frequency of 3 piece / cm-80 piece / cm in the range of. More excellent designability can be realized by making the frequency of formation of a hairline in a hairline orthogonal direction into the range of 3 piece / cm-80 piece / cm. When the frequency of formation of the hairline in the hairline orthogonal direction is less than 3 / cm, the density of the hairline becomes too low, and the possibility of not being able to recognize the hairline increases. On the other hand, when the formation frequency of the hairline in the hairline orthogonal direction exceeds 80 pieces / cm, the density of the hairline becomes too high and does not become a neat hairline, and the designability as a hairline may be impaired. have.

The lower limit of the existence frequency of the recessed part 101 in the range of 1 cm width along the hairline orthogonal direction becomes like this. More preferably, it is 10 piece / cm, More preferably, it is 15 piece / cm. Moreover, the upper limit of the existence frequency of the recessed part 101 in the range of arbitrary 1 cm width | variety along a hairline orthogonal direction becomes like this. More preferably, it is 70 piece / cm, More preferably, it is 65 piece / cm.

In addition, the presence frequency of such a recessed part 101 observes the surface of the zinc-based electroplating layer 13 with the laser microscope whose display resolution of a height direction is 1 nm or more, and the display resolution of the width direction is 1 nm or more, It can specify by counting the number of recessed parts 101 with respect to the arbitrary 1 mm width range. That is, by measuring 20 or more arbitrary ranges of 1 mm width with respect to the surface of the zinc-based electroplating layer 13, and dividing the total number of the recessed parts 101 in each range by the measurement number number, The average frequency of the recesses 101 can be obtained.

As mentioned above, the surface shape of the zinc-based electroplating layer 13 which concerns on this embodiment was demonstrated in detail, referring FIG.

(About another structural example of a zinc-based electroplated steel plate)

Here, in FIG. 1A and FIG. 1B, the case where the recessed part 101 is provided only in the zinc type electroplating layer 13 was shown. However, in the zinc-based electroplated steel sheet 1 according to the present embodiment, as shown in FIG. 7A and FIG. 7B, the recessed portion for forming the hairline drawn in a predetermined direction also on the surface of the steel sheet 11 ( 105) may be provided.

In more detail, as shown to FIG. 7A and 7B, the position corresponding to the hairline (that is, the recessed part 101) in the zinc-based electroplating layer 13 on the surface of the steel plate 11 You may provide the recessed part 105 in the.

Here, as shown in FIGS. 1A and 1B, when the concave portion 101 is provided only in the zinc-based electroplating layer 13, and as shown in FIGS. 7A and 7B, the surface of the steel plate 11 may also be used. When providing the recessed part 105, when manufacturing a zinc-based electroplating steel plate 1, the timing of a hairline process differs. The difference of the timing of such a hairline process is demonstrated in detail again below.

It can be confirmed by a well-known method whether the recessed part 105 exists in the position corresponding to the recessed part 101 formed in the zinc-based electroplating layer 13 among the surfaces of the steel plate 11. As such a confirmation method, for example, the method of observing the zinc-based electroplating steel sheet 1 from the cross-sectional direction, the photograph of the zinc-based electroplating layer 13 taken from the surface, and the hydrochloric acid to which the inhibitor is added, the zinc-based electroplating layer After removing only (13), the method of comparing the photograph taken from the surface, etc. are mentioned.

(About the manufacturing method of a zinc-based electroplated steel plate)

Then, the manufacturing method of the zinc-based electroplating steel plate which concerns on this embodiment as described above is demonstrated easily.

<Production method-the first>

Below, first, the manufacturing method of the zinc-based electroplating steel plate 1 which has a structure as shown to FIG. 1A and FIG. 1B is demonstrated briefly.

In this case, first, the steel sheet 11 whose surface roughness is adjusted is subjected to degreasing with an alkaline solution and pickling with an acid using hydrochloric acid, sulfuric acid or the like. Then, a zinc-based electroplating layer 13 is formed on the surface of the steel sheet 11. Here, the adjustment of the surface roughness of the steel plate 11 can use a well-known method, for example, the method of rolling the steel plate 11 with the roll adjusted so that surface roughness might become a desired range, and transferring surface roughness. Method 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 ginate bath, a cyanide bath, a pyrophosphate bath, a boric acid bath, a citric acid bath, other complex baths, a combination thereof, and the like can be used. In addition, by adding at least one mono- or complex ion selected from Co, Cr, Cu, Fe, Ni, P, Sn, Mn, Mo, V, W, Zr, in addition to Zn ions, The electro zinc alloy plating layer 13 containing a desired amount of Co, Cr, Cu, Fe, Ni, P, Sn, Mn, Mo, V, W, and Zr can be formed. In addition, in order to control stabilization of ions in the plating bath and to control the plating properties, it is more preferable to add an additive to the plating bath.

In addition, what is necessary is just to select suitably the composition of the said electroplating bath, temperature, flow rate, the current density at the time of plating, an energization pattern, etc. so that it may become a desired plating composition, and is not specifically limited. In addition, control of the thickness of a zinc plating layer and an electrogalvan alloy plating layer can be performed by adjusting a current value and time in the range of the current density which becomes a desired composition.

The hairline which concerns on this embodiment is formed with respect to the plated steel plate 11 provided with the zinc-based electroplating layer 13 obtained by the above. The method for applying the hairline is not particularly limited, and various known methods can be used. Such known methods include, for example, a method of polishing with a polishing belt, a method of polishing with an abrasive brush, a method of transferring to a roll with a texture, and a predetermined grinding machine, similarly to the case of applying a hairline to a stainless steel. And the like can be mentioned.

In addition, the depth and frequency of a hairline can be controlled to a desired state by adjusting the particle size of a polishing belt and an abrasive brush, the depth of the texture of a roll, and a rolling force, a relative speed, and a frequency | count.

The unevenness | corrugation by the crystal grain of plating exists in the surface of the zinc-based electroplating layer 13 which formed the hairline as mentioned above. So, in the manufacturing method of the zinc-based electroplating steel plate which concerns on this embodiment, after formation of a hairline, until the surface shape of the zinc-based electroplating layer 13 turns into the surface shape which satisfy | fills the various conditions as mentioned above, By the known method, the surface of the zinc-based electroplating layer 13 is ground, rolled, or rolled with a roll whose surface roughness is adjusted.

Here, in the above grinding treatment, polishing treatment or rolling treatment, the non-hairline portion around the remaining portion is appropriately ground so that the portion where the unevenness of the crystal grains of the plating remains corresponds to the hairline portion. Polishing, or rolling. As a result, as shown schematically in FIG. 2, the treated portion becomes the smooth portion 113 in which the unevenness of the crystal grains of the plating is suppressed, and on the other hand, the concave portion that forms the hairline without being treated ( 101 becomes the rough part 111 in which the unevenness | corrugation of the crystal grain of plating remains.

On the contrary, in the above grinding treatment, polishing treatment, or rolling treatment, when only a portion of the hairline portion is subjected to the selective grinding, polishing, and rolling treatment, the hairline as schematically shown in FIG. The concave portion 101 for forming the concave portion becomes the smooth portion 113 in which the unevenness of the crystal grains of plating is suppressed. On the other hand, the non-hairline part which has not been processed becomes the grandfather 111.

Such a case shown in FIG. 6 will be described in the case of forming by polishing with an abrasive brush. Although the surface of the zinc-based electroplating layer 13 before hairline formation is flat, it is in the state covered with the unevenness | corrugation of the crystal grain of plating. In this state, the surface of the zinc-based electroplating layer 13 is polished with an abrasive brush, whereby the shaved portion becomes a hairline (concave portion 101). Moreover, in this hairline, since the convex part of the crystal grain of plating is also shaved off by grinding | polishing, surface roughness becomes lower than the original state, and it becomes smooth. That is, formation of a hairline and surface roughness adjustment in a hairline are performed simultaneously. On the other hand, in the surface of the zinc-based electroplating layer 13, the flat part (non-hairline part 103) which was not shaved by the abrasive brush is as it is, and the unevenness | corrugation of the crystal grain of plating remains.

By the above, as shown in FIG. 6, the non-hairline part 103 where the rough part 111 predominantly exists and the work adhesiveness is ensured, and the smooth part 113 predominantly exist, and high concave is concave. The part 101 will coexist.

As mentioned above, the organic resin is coat | covered on the surface of the zinc-based electroplating layer 13 which provided the hairline as needed. 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 zinc-based electroplating layer 13 It is preferable that the leveling after reflecting the surface shape of) is slow. That is, it is preferable that it is a paint with a low viscosity at high shear rate, and a high viscosity at low shear rate. Specifically, it is preferable to have 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].

In order to adjust shear viscosity in the above ranges, if it is the coating material which used aqueous emulsion resin, for example, it can add and adjust a hydrogen bondable viscosity modifier. Since the viscosity modifier of such a hydrogen bondability is mutually restrained by a hydrogen bond at the low shear rate, the viscosity of a paint can be improved, but since a hydrogen bond is cut | disconnected at a high shear rate, a viscosity falls. Thereby, it becomes possible to adjust to the shear viscosity according to the coating conditions required.

In addition, the method of coating an organic resin is not specifically limited, A known method can be used. For example, it can apply | coat by the spraying method, the roll coater method, the curtain coater method, the die coater method, or the immersion pulling method using the coating material adjusted to the above-mentioned viscosity, and can form by natural drying or baking drying. In addition, what is necessary is just to determine a drying temperature, a drying time, baking temperature, and baking time suitably so that the organic resin coating layer 15 to form may have desired performance. At this time, when the temperature increase rate is low, the time from the softening point of the resin component to the completion of baking becomes long, and the leveling proceeds. Therefore, the temperature increase rate is preferably faster.

<Production method-second>

Next, the manufacturing method of the zinc-based electroplating steel plate which has a structure as shown to FIG. 7A and 7B is demonstrated easily.

In such a case, the steel plate which completed until the adjustment of surface roughness is used similarly to said "manufacturing method-first." And the steel plate 11 is obtained by forming a hairline with respect to this steel plate, before performing a plating process. The method of applying hairline to the steel sheet is not particularly limited, but a method of polishing with an abrasive belt, a method of polishing with an abrasive brush, a method of transferring to a roll provided with a texture, a method of grinding with a predetermined grinding machine, or the like may be used. It is preferable. As a result, a rough portion 105 as shown in FIGS. 7A and 7B is formed on the surface of the steel plate 11.

Subsequently, the zinc-based electroplating layer 13 is formed on the steel plate 11 on which the hairline is formed. Since the formation method of the zinc-based electroplating layer 13 can be performed similarly to the said "manufacturing method-first", detailed description is abbreviate | omitted below. By electroplating the steel plate 11 on which the hairline was formed, the zinc-based electroplating layer 13 is formed while maintaining the surface shape of the steel plate 11 on which the hairline is formed. That is, the zinc-based electroplating layer 13 having the hairline of the position and shape corresponding to the hairline of the steel plate 11 in plan view is formed.

On the surface of the zinc-based electroplating layer 13 formed as mentioned above, plating crystal grains exist similarly to the said "manufacturing method-first." That is, the surface of the zinc-based electroplating layer 13 at this point is in a state in which both the recessed portion 101 and the non-hairline portion 103 are covered with irregularities of the crystal grains of the plating.

So, in this manufacturing method, after formation of the zinc-based electroplating layer 13, by the well-known method until the surface shape of the zinc-based electroplating layer 13 turns into the surface shape which satisfy | fills the various conditions as mentioned above. The surface of the zinc-based electroplating layer 13 is ground, rolled or rolled with a roll having adjusted surface roughness. Thereby, the rough part 111 and the smooth part 113 are formed in the surface of the zinc-based electroplating layer 13 similarly to the said "manufacturing method-first."

More specifically, for example, when polishing with an abrasive brush, only the non-hairline part 103 is mainly polished among the surfaces of the zinc-based electroplating layer 13. As a result, in the non-hairline part 103 polished with an abrasive brush, since the convex part of a crystal grain is shaved, surface roughness becomes lower than the original state, it becomes smooth, and the smooth part 113 predominantly exists. On the other hand, in the recessed part 101 which forms the recessed part which is hard to reach an abrasive brush, the unevenness | corrugation of the crystal grain of plating remains as it has been originally. By the above, the non-hairline part 103 where the rough part 113 predominantly exists and the work adhesiveness is ensured, and the smooth part 111 predominantly exists, and the recessed part 101 with high glossiness coexists. .

Subsequently, as shown in FIG. 7B, the organic resin is coated on the surface of the zinc-based electroplating layer 13 to which the hairline has been applied. Since formation of such an organic resin coating layer 15 can be performed similarly to the said "manufacturing method-first", detailed description is abbreviate | omitted below.

In the above, the manufacturing method of the zinc-based electroplating steel plate which concerns on this embodiment was demonstrated.

In addition, as the zinc-based electroplated steel sheet 1, when the form shown in FIG. 1A and the form shown in FIG. 7A are compared, the form shown in FIG. 7A has a smooth portion not only in the plane but also in the depth direction. In addition, since a depth arises in a hairline, high glossiness (texture) is easy to be obtained. For the same reason, even when the form shown in FIG. 1B is compared with the form shown in FIG. 7B, the higher glossiness (texture) of the form shown in FIG. 7B is likely to be obtained.

(About the specific example of a zinc type electroplating layer)

Next, the specific example of the zinc-based electroplating layer 13 which concerns on this embodiment formed by the method as demonstrated above is demonstrated easily, referring FIG. 8A-FIG.

8A to 9 are examples of microscope images when the surface of the zinc-based electroplating layer 13 is observed under an electron microscope. FIG. 10: is a graph which shows the measurement example of the surface height of the zinc-based electroplating layer 13 which the zinc-based electroplating steel plate 1 which concerns on this embodiment has. 11 is an example of a microscope image when the surface of the zinc-based electroplating layer of a general zinc-based electroplated steel sheet is observed under an electron microscope. In addition, the specific example shown below is a specific example when the recessed part 101 which forms a hairline is comprised by the rough part 111, and the non-hairline part 103 is comprised by the smooth part 113. FIG. .

When the zinc-based electroplating layer 13 is formed by the manufacturing method as described above, for example, a zinc-based electroplating layer 13 having a surface shape as shown in FIG. 8A can be formed. In the electron micrograph shown in FIG. 8A, the region corresponding to the recessed portion 101 and the region corresponding to the non-hairline portion 103 are distributed as shown in FIG. 8B. In addition, in FIG. 8B, the area | region corresponding to the non-hair line part 103 is shown by the diagonal line.

In FIG. 9, the zinc-based electroplating layer 13 shown to FIG. 8A WHEREIN: The enlarged part of the recessed part 101 and the expanded part of the non-hairline part 103 were shown. 9B, which is an enlarged view of the concave portion 101 in FIG. 9A, it can be seen that a large number of particulate matters exist in the center of the photograph. This particulate object is the crystal grain of plating. On the other hand, when looking at FIG. 9 (C) which is an enlarged view of the non-hair line part 103 in FIG. 9A, the unevenness | corrugation by the crystal grain of plating which exists in the enlarged view of the recessed part 101 is shown. It turns out that this does not exist at all.

10 is a measurement result of the surface height in the part in which the recessed part 101 and the non-hairline part 103 are continuous, the horizontal axis of FIG. 10 is a measurement length, and the vertical axis of FIG. 10 is a surface height. . As apparent from Fig. 10, the height difference between the non-hairline portion 103 and the recessed portion 101 is about 0.8 mu m. It can be seen that the average height difference between the concave portion 101 and the non-hairline portion 103 in each portion is 0.3 µm or more.

On the other hand, when the surface of the zinc-based electroplating layer which a general zinc-based electroplating steel sheet has is observed under an electron microscope, as shown in FIG. 11 (A), the ratio of the zinc-based electroplating layer 13 according to the present embodiment has. It can be seen that the hairline section 103 does not exist. In addition, as shown in FIG. 11B, it can be seen that the crystal grains of the plating are widely distributed on the surface of the general zinc-based electroplating layer.

EXAMPLE

EMBODIMENT OF THE INVENTION Hereinafter, the effect of this invention is demonstrated to an example of invention more specifically. In addition, the area S _A and S _B in Table 1 and Table 3 mentioned later are each area (a dimensionless value) in the case where the total area of an observation visual field is 1.0, respectively, and area S _A + S _B = 1.0. In addition, in the column of "the total area of which RaA is more than 200 nm and 2000 nm or less" in Table 1 and Table 3, the left column is the ratio of the area (maximum 1.0) which satisfies the roughness condition in area S _A , and the right column is roughness condition It is the real area to satisfy. Accordingly, it is the area _A S × [jwacheukran] = [right column. Similarly, Table 1 and Table 3, and the ratio (maximum 1.0) in the area of "RaB a total area less than 200㎚ 5㎚" means of, jwacheukran of the illumination condition is satisfied in an area S _B, right column is illumination condition in the It is the real area to satisfy. Therefore, the area S _B × [left column] = [right column]. In addition, the average height difference in Table 1 and Table 3 is an average value of (DELTA) h shown in FIG. 2 or FIG. That is, the difference Δh between the average surface height of one jaw portion 111 and the average surface height of the smooth portion 113 adjacent to the jaw portion 111 is obtained and the angles of the jaws 111 and the smooth portion 113 are determined. It calculates about each combination. And the average value of calculated | required angle (DELTA) h was calculated | required, and this was made into the average height difference of Table 1 and Table 3.

In addition, the content of this invention is not restrict | limited by the content described in the Example shown below.

(Experimental Example 1: Example in which Grandparents Form Hairline)

As the steel sheet having a thickness of 0.6 mm, SPCD which is for drawing is used in a cold rolled steel sheet specified in JIS G 3141, using a Na ₄ SiO ₄ treatment liquid having a concentration of 30 g / L and a treatment liquid of 60 ° C. and a current density of 20 A /. in dm ^2, the processing time was 10 seconds, conditions electrolytic degreasing and washing. Then, by immersing the electrolytic degreasing a steel material, 10 to the H ₂ SO ₄ aqueous solution at a concentration 50g / L of 60 ℃ seconds, again washed with water, was subjected to the plating pretreatment.

Next, about the steel plate samples No. 1 to No. 20 shown in the following Table 1, before forming the zinc-type electroplating layer 13, hairline was formed in the surface of the steel plate by rolling. In addition, the rolling method was made to roll the rolling roll which gave the surface to the design surface. The rolling speed was 200 mpm, and the rolling roll diameter was 500 mm. In addition, about the steel sample of Nos. 21-23, before forming the zinc-type electroplating layer 13, the hairline was formed in the surface of the steel plate by grinding.

Subsequently, zinc-based electroplating of the composition shown in following Table 1 was performed about all the steel plate samples, and the zinc-based electroplating layer 13 was formed. Here, in the following Table 1, the addition element described in the column of "plating composition" is an element added in the electroplating liquid which has zinc as a main component, and when such a column is blank, what electroplated was performed. it means.

The Zn-Ni plating films (Table 1: Nos. 1 to 13, 17 to 21), when plated with a bath temperature of 50 ° C. and a current density of 50 A / dm ^2, are Zn sulfate monohydrate with a ratio of the composition shown in Table 1 below. Using a plating bath of pH 2.0 containing a total of Zn sulfate and Ni sulfates and a total of 1.2 M of sulfate and Ni sulfates, with 50 g / L of anhydrous sodium sulfate, the adhesion amount was adjusted to the values shown in Table 1. It formed by adjusting plating time.

The Zn-Fe plated film (Table 1: No. 14) was coated with a bath temperature of 50 ° C. and a current density of 50 A / dm ² , and the Zn sulfate monohydrate and the Fe (II) sulfate were diluted in a ratio of the composition shown in Table 1 below. Using the plating bath of pH 2.0 containing the total amount of Zn sulfate and Fe (II) sulfate heptahydrate which adjusted cargo, and pH 2.0 containing 50 g / L of anhydrous sodium sulfate, so that an adhesion amount may be set to the value shown in Table 1, It formed by adjusting plating time.

The Zn-Co plated film (Table 1: No. 15), when plated at a bath temperature of 50 ° C. and a current density of 50 A / dm ² , adjusts Zn sulfate and Co sulfate sulfates at a ratio of the composition shown in Table 1 below. The plating time was adjusted by using a plating bath of pH 2.0 containing a total of Zn sulfate and co sulfate heptahydrates of 1.2 M and 50 g / L of anhydrous sodium sulfate, so that the adhesion amount was the value shown in Table 1. did.

The Zn plating film (Table 1: No. 16) was prepared using a plating bath of pH 2.0 containing 1.2 M of Zn sulfate hydrate and 50 g / L of anhydrous sodium sulfate, and having a bath temperature of 50 ° C. and a current density of 50 A / dm ^2. When it plated by, it formed by adjusting plating time so that an adhesion amount might become the value shown in Table 1.

In Example No. 22 using Ni and Fe as an additional element, when the plating is performed at a bath temperature of 50 ° C. and a current density of 50 A / dm ² , Zn sulfate and Ni sulfate hexahydrate and sulfuric acid are dissolved in a ratio of the composition shown in Table 1 below. Using a plating bath having a pH of 2.0 containing a total of 1.2 M of Zn sulfate, Ni sulfate, and 6 sulfate of Fe (II) sulfate and 50 g / L of anhydrous sodium sulfate, in which Fe (II) heptahydrate was adjusted, The plating time was adjusted and formed so that an adhesion amount might become the value shown in Table 1.

In Example No. 23 containing Ni, Fe, and Co as an additional element, when the plating is performed at a bath temperature of 50 ° C. and a current density of 50 A / dm ² , Zn sulfate and Ni sulfate hexahydrates in a ratio of the composition shown in Table 1 below. Zn sulfate, Ni sulfate, Ni sulfate, Fe (II) sulfate, Co sulfate, cobalt sulfate total of 1.2 M and 50 g / L of anhydrous sodium sulfate The plating time was adjusted and formed using the plating bath of pH2.0 containing so that adhesion amount might be set to the value shown in Table 1.

In addition, at the time of all the said plating processes, the plating liquid was made to flow so that the relative flow velocity with respect to a steel plate might be set to 1 m / sec. In addition, the composition of the obtained plating film was confirmed by immersing and peeling the plated steel plate in 10 mass% hydrochloric acid in which the inhibitor (NO.700AS by Asahi Chemical Co., Ltd.) was put, and carrying out the dissolution, and analyzing the melted solution by ICP.

In addition, all the said reagent used the general reagent (zinc sulfate heptahydrate, anhydrous sodium sulfate, hydrochloric acid, sulfuric acid (pH adjustment)).

In addition, about the steel samples of No.1-No.23, after forming the zinc-type electroplating layer 13, the surface of the zinc-based electroplating layer 13 is brush-polished and the recessed part 101 shown in Table 1 is carried out. And polishing conditions (particle size, polishing force, polishing frequency, etc.) of the polishing paper were adjusted appropriately so as to form the surface shape of the non-hairline portion 103. This formed the surface shape of the zinc-based electroplating layer 13 in which the recessed part 101 is comprised by the rough part 111, and the non-hairline part 103 is comprised by the smooth part 113. As shown in FIG.

Moreover, the boundary between the rough part 111 and the smooth part 113 is a hairline orthogonal direction and the zinc-based electroplating layer in the cross section of a plate thickness direction in the range of 1 cm of observation width | variety along the said hairline orthogonal direction. It was assumed that the height of 1/3 of the maximum height Ry minus the lowest point H ₀ from the highest point H ₁ of (13) is on an imaginary straight line parallel to the hairline orthogonal direction.

The surface roughness, surface height, number of hairlines, area ratio and the like in the zinc-based electroplating layer 13 shown in Table 1 have a display resolution of 1 nm or more in the height direction and a display resolution of 1 in the width direction. Before and after dissolving by immersion in 10 mass% hydrochloric acid containing an inhibitor (NO.700AS manufactured by Asahi Chemical Co., Ltd.) using a laser microscope / VK-9710 manufactured by Keyence Co. It calculated from the weight difference of.

The transparent organic resin coating layer was formed with respect to the said plated steel plate which provided the hairline. The transparent organic resin was formed by the following method. That is, a urethane resin (made by ADEKA Corporation, HUX-232), an isocyanate (made by Dai-Ichi Kogyo Co., Ltd., elastron BN69), and a hardening catalyst (made by Dai-Ichi Kogyo Co., Ltd., elastron CAT-21) It mixed so that mass ratio might be 100: 10: 0.5. Then, polyethylene wax (made by Mitsui Chemical Co., Ltd., Chemipearl W500) was added and stirred so that the density | concentration in a dry film might be set to 2 mass%. In addition, the obtained mixture was diluted with water to prepare a treatment liquid having various concentrations and viscosities. These processing liquids were apply | coated to the steel plate surface by the roll coater. At this time, it adjusted so that dry film thickness might become thickness shown in following Table 1. The coated steel plate was hold | maintained for 30 second in the hot stove maintained at 280 degreeC. The achieved temperature of the steel sheet was set to 210 ° C, and cooled by spray-spraying water after heating.

About each before and after forming the organic resin coating layer 15, glossiness G60 was measured with the glossmeter (Grossmeter UGV-6P made from Suga Shikenki). In addition, at the time of a measurement, two types of glossiness Gl of the hairline direction and glossiness Gc of the hairline orthogonal direction were measured. These obtained results were put together in the following Table 2, and were shown.

Corrosion resistance of the obtained zinc-based electroplated steel sheet was evaluated by the following method.

That is, the test piece of width 70mm x length 150mm was produced from each obtained zinc-type electroplating steel plate. The edge and back surface were tape sealed and the salt spray test (JIS Z2371) was done. And the white rust-generating area ratio of the non-sealing part after 24 hours was observed visually, and the following evaluation criteria evaluated. The white rust-generating area rate is a percentage of the area of the white rust-generating site with respect to the area of the observation site. The obtained result was put together in the following Table 2 and shown.

(Evaluation standard)

5: less than 10% of white blue incidence

4: White rust incidence 10% or more and less than 25%

3: 25% or more of white rust incidence less than 50%

2: 50% or more of white rust incidence less than 75%

1: 75% or more occurrence of white rust

In addition, the process adhesiveness (adhesion with an organic resin coating layer) of the obtained zinc-based electroplated steel sheet was evaluated by the following method.

That is, the test piece of width 50mm x length 50mm was produced from each obtained zinc-type electroplating steel plate. After performing 180 degree bending process with respect to the obtained test piece, the tape peeling test was done with respect to the outer side of a bending part. The external appearance of the tape peeling part was observed with the loupe of 10 times the enlargement ratio, and the following evaluation criteria evaluated. The bending process was performed by sandwiching a 0.5 mm spacer in 20 degreeC atmosphere. The obtained result was put together in the following Table 2 and shown.

(Evaluation standard)

5: peeling is not seen in coating film

4: Peeling is seen by very few coating films (peel area≤2%)

3: Peeling is seen on some coating films (2% <peeling area ≤ 10%)

2: peeling is seen on the coating film (10% <peel area≤20%)

1: Peeling is seen on the coating film (peel area> 20%)

In the steel samples of Nos. 1 to 23, in the comparative example of No. 2, both the average height difference and the area ratio did not satisfy the requirements, resulting in low work adhesiveness. Moreover, in the comparative example of No. 5, both the average height difference and area ratio did not satisfy | fill a prescription | regulation, and the result was that corrosion resistance was low. In addition, in the comparative example of No. 13, Gc / Gl did not satisfy | fill a prescription | regulation, and the result was a lack of a metallic feeling.

As apparent from Table 2, the zinc-based electroplated steel sheet according to the embodiment of the present invention has a predetermined corrosion resistance while using an inexpensive steel, has a hairline appearance, and is excellent in metallic feeling and work adhesion. Can be.

(Experimental Example 2: Example of Smoothing Part to Form Hairline)

As the steel sheet, SPCD (thickness 0.6 mm) for drawing among the cold rolled steel sheets specified in JIS G 3141, using a Na ₄ SiO ₄ treatment liquid having a concentration of 30 g / L, the treatment liquid at 60 ° C. and the current density of 20 A / dm ² , electrolytic degreasing and washing with water were carried out under conditions of a treatment time of 10 seconds. Then, by immersing the electrolytic degreasing a steel material, 10 to the H ₂ SO ₄ aqueous solution at a concentration 50g / L of 60 ℃ seconds, again washed with water, was subjected to the plating pretreatment.

Subsequently, zinc-based electroplating of the composition shown in following Table 3 was performed about all the steel plate samples, and the zinc-based electroplating layer 13 was formed. Here, in the following Table 3, the "addition element" described in the column of "plating composition" is an element added in the electroplating liquid. When this column is blank (Table 3: No. 33), it means that electrogalvanization was performed.

In addition, when Zn-Ni plating film (Table 3: No.31, 32, 34-40) is plated by 50 degreeC of bath temperature and current density of 50A / dm <^2> , Zn sulfate is applied by the ratio which becomes the composition of Table 3 below. Table 2 shows the amount of plating adhesion after hairline formation using a plating bath of pH 2.0 containing a total of ZM sulfate and Ni sulfate hexate adjusted with cargo and Ni sulfate heptahydrate, totaling 1.2 M and 50 g / L of anhydrous sodium sulfate. The plating time was adjusted and formed so that it might become the value shown in 3.

The Zn-Fe plating film (Table 1: No. 41) was coated with a bath temperature of 50 ° C. and a current density of 50 A / dm ² , and the Zn sulfate monohydrate and the Fe (II) sulfate were diluted in a ratio of the composition shown in Table 3 below. The plating adhesion amount after hairline formation was adjusted using the plating bath of pH 2.0 containing the total amount of Zn sulfate and Fe (II) sulfate heptahydrates and the pH 2.0 containing 50 g / L of anhydrous sodium sulfate, in which the cargo was adjusted. The plating time was adjusted and formed so that it might become the value shown.

The Zn-Co plating film (Table 1: No. 42) is adjusted to Zn sulfate and Co sulfate hydrates in a ratio of the composition shown in Table 3 below when plating at a bath temperature of 50 ° C. and a current density of 50 A / dm ² . The plating was carried out using a plating bath of pH 2.0 containing a total of 1.2 M of Zn sulfate and Co sulfate hemihydrate and 50 g / L of anhydrous sodium sulfate, so that the plating adhesion after hairline formation was at the value shown in Table 3. Formed by adjusting the time.

In Example No. 43 using Ni and Fe as an additional element, when the plating is performed at a bath temperature of 50 ° C. and a current density of 50 A / dm ² , Zn sulfate and Ni sulfate hexahydrate and sulfuric acid are dissolved in a ratio of the composition shown in Table 3 below. Using a plating bath having a pH of 2.0 containing a total of 1.2 M of Zn sulfate, Ni sulfate, and 6 sulfate of Fe (II) sulfate and 50 g / L of anhydrous sodium sulfate, in which Fe (II) heptahydrate was adjusted, The plating time was adjusted and formed so that the plating adhesion amount after hairline formation might be set to the value shown in Table 3.

In Example No. 44 containing Ni, Fe, and Co as an additional element, when the plating is performed at a bath temperature of 50 ° C. and a current density of 50 A / dm ² , Zn sulfate and Ni sulfate hexahydrates in a ratio of the composition shown in Table 3 below. Zn sulfate, Ni sulfate, Ni sulfate, Fe (II) sulfate, Co sulfate, cobalt sulfate total of 1.2 M and 50 g / L of anhydrous sodium sulfate The plating time was adjusted and formed so that the plating adhesion amount after hairline formation might be set to the value shown in Table 3 using the plating bath of pH2.0 it contains.

In addition, at the time of all the said plating processes, the plating liquid was made to flow so that the relative flow velocity with respect to a steel plate might be set to 1 m / sec. In addition, the composition of the obtained plating film was confirmed by immersing and peeling the plated steel plate in 10 mass% hydrochloric acid in which the inhibitor (NO.700AS by Asahi Chemical Co., Ltd.) was put, and carrying out the dissolution, and analyzing the melted solution by ICP.

In addition, all the said reagent used the general reagent (zinc sulfate heptahydrate, anhydrous sodium sulfate, hydrochloric acid, sulfuric acid (pH adjustment)).

Subsequently, about the steel plate samples of Nos. 31 to 34 shown in Table 3 below, after the zinc-based electroplating layer 13 was formed, the hairline was formed on the surface of the zinc-based electroplating steel sheet 1 by rolling. Formed. In addition, the rolling method made it the method of pressing the rolling roll which gave the surface to the design surface (namely, the surface of the zinc-type electroplating layer 13) of the zinc-type electroplating steel plate 1. The rolling speed was 50 mpm. On the rolled roll surface, a continuous abrasive line was provided as a shape by fixing commercially available sand paper for belt sanders to a grinder, and rotating a roll. The number of hairlines was adjusted by the spacing of such abrasive lines, and the hairline depth was adjusted by the roughness of the sand paper and the rolling load. Commercially available SiC was used for abrasive grains.

In addition, about the steel plate samples No.35-No.38 and 41-44 shown in following Table 3, after forming the zinc-type electroplating layer 13, the hairline was formed in the surface of the steel plate by grinding. In addition, the grinding method was made to roll into the design surface (namely, the surface of the zinc-type electroplating layer 13) which has the zinc-type electroplating layer 13, rotating the roll which gave the surface a shape. The grinding brush was rotated in the reverse direction to the plate direction of the steel sheet sample. Hairline depth was adjusted by brush material, rotation speed and load between brush-steel sheet. In addition, the hairline density was adjusted with the actual diameter and density of a brush.

According to the above procedures, the surface shape of the zinc-based electroplating layer 13 in which the recessed part 101 is comprised by the smooth part 113 and the non-hairline part 103 is comprised by the rough part 111 is formed. did.

In addition, for reference, Comparative Examples No. 39 and No. 40 in the case of temper rolling a steel sheet and then forming a hairline by brush polishing or rolling were also prepared.

Moreover, the boundary between the rough part 111 and the smooth part 113 is a hairline orthogonal direction and the zinc-based electroplating layer in the cross section of a plate thickness direction in the range of 1 cm of observation width | variety along the said hairline orthogonal direction. It was assumed that the height of 1/3 of the maximum height Ry minus the lowest point H ₀ from the highest point H ₁ of (13) is on an imaginary straight line parallel to the hairline orthogonal direction.

Here, in the zinc-based electroplating layer 13 shown in Table 3, the display resolution in the height direction is 1 nm or more, and the display resolution in the width direction is 1 in the various surface roughness, surface height, hairline number, area ratio, and the like. Before and after dissolving by immersion in 10 mass% hydrochloric acid containing an inhibitor (NO.700AS manufactured by Asahi Chemical Co., Ltd.) using a laser microscope / VK-9710 manufactured by Keyence Co. It calculated from the weight difference of.

The transparent organic resin coating layer was formed with respect to the said plated steel plate which provided the hairline. The transparent organic resin was formed by the following method. That is, a urethane resin (made by ADEKA Corporation, HUX-232), an isocyanate (made by Daiichi Kogyo Co., Ltd., elastron BN69), and a hardening catalyst (made by Daiichi Kogyo Co., Ltd., elastron CAT-21) are solid content It mixed so that mass ratio might be 100: 10: 0.5. Thereafter, polyethylene wax (manufactured by Mitsui Chemical Co., Ltd., Chemipearl W500) was added so as to have a concentration of 2% by mass in the dry film, followed by stirring. In addition, the obtained mixture was diluted with water to prepare a treatment liquid having various concentrations and viscosities. These treatment liquids were applied to the steel plate surface with a roll coater. At this time, it adjusted so that dry film thickness might become thickness shown in following Table 1. The coated steel plate was hold | maintained for 30 second in the hot stove maintained at 280 degreeC. The achieved temperature of the steel sheet was 210 ° C., and after heating, the steel plate was cooled by spray-spraying water.

About each of the zinc-based electroplated steel sheets obtained as mentioned above, it carried out similarly to Experimental Example 1, and evaluated glossiness, corrosion resistance, and work adhesiveness. Evaluation methods and evaluation criteria are the same as in Experimental Example 1. The obtained result was put together in the following Table 4 and shown.

In the steel samples of Nos. 31 to 44, in the comparative example of No. 34, both the average height difference and the area ratio did not satisfy the requirements, resulting in low work adhesiveness. Moreover, in the comparative example of No. 36, area ratio did not satisfy | fill a prescription | regulation, but the result was adhesiveness low.

In the comparative example of No. 38, the area ratio and Gc / Gl did not satisfy the regulations, resulting in a lack of metallic feel.

The comparative example of No. 39 is brush-polished after rough rolling, and No. 40 is rolled after rough rolling. All of these resulted in the fact that the work adhesiveness was very low because the irregularities of the plated particles were eliminated.

As is apparent from Table 4, the zinc-based electroplated steel sheet according to the present invention has a predetermined corrosion resistance, has a hairline appearance, and is excellent in metallic feeling and workability while using an inexpensive steel material.

As mentioned above, although preferred embodiment of this invention was described in detail, referring an accompanying drawing, this invention is not limited to this example. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs may be able to coat various modifications or modifications within the scope of the technical idea described in the claims. It is understood that it belongs to the technical scope of the invention.

According to the present invention, it is possible to provide a zinc-based electroplated steel sheet having a predetermined corrosion resistance, having a hairline appearance, and having excellent metallic feel and workability while using an inexpensive steel material.

1: zinc-based electroplated steel sheet
11: steel plate
13: zinc-based electroplating layer
15: organic resin coating layer
101, 105: recess
103: hairless part
111: grandfather
113: smoothing part

Claims (11)

Steel plate,
It is provided on the at least one surface of the said steel plate, Comprising: The zinc-type electroplating layer provided with the hairline which is a recessed part extended in a predetermined direction,
The zinc-based electroplating layer is composed of a rough portion (A) and a smooth portion (B),
The said roughening part _A contains the area | region whose average surface roughness Ra _A is more than 200 nm and 2000 nm or less,
The said smooth part B contains the area whose average surface roughness Ra _B is more than 5 nm and 200 nm or less,
The boundary between the rough portion A and the smooth portion B,
And the hair line perpendicular to the direction orthogonal to the predetermined direction and in a cross section of the thickness direction, and the low point H ₀ Oh H ₁ from the highest point of the associated electroplating layer in the range of observation width 1㎝ along the hair line perpendicular to the direction Suppose the height is 1/3 of the maximum height Ry minus and is on an imaginary straight line parallel to the hairline orthogonal direction,
When the area of the rough portion _A is S _A and the area of the smooth portion B is S _B in the same area unit, the area ratio S _B / S _A is in the range of 0.6 to 10.0,
The average elevation difference between the said rough part A and the said smooth part B adjacent to the said rough part A is 0.3 micrometer-3.0 micrometers,
Zinc-based electroplated steel sheet. The total area of the area | region in which the said average surface roughness Ra _A in the said roughening part _A is more than 200 nm and 2000 nm or less is 85% or more with respect to the area S _A of the said roughening part A, Furthermore,
The total area of the area | region where the said average surface roughness Ra _B in the said smooth part _B is more than 5 nm and 200 nm or less is 65% or more with respect to area S _B of the said smooth part B,
Zinc-based electroplated steel sheet. The method of claim 1 or 2, wherein the jaw (A) is formed in the hairline,
The average length along the extending direction of the hairline is 1 cm or more,
Zinc-based electroplated steel sheet. The method of claim 1 or 2, wherein the smoothing portion (B) is formed in the hairline,
The average length along the extending direction of the hairline is 1 cm or more,
Zinc-based electroplated steel sheet. The said hairline exists in the range of the arbitrary 1 cm width | variety along the said hairline orthogonal direction at the frequency of 3 pieces / cm-80 pieces / cm on average,
Zinc-based electroplated steel sheet. The recessed part of any one of Claims 1-5 in which the recessed part is formed in the position corresponding to the said hairline in the said zinc-type electroplating layer in the surface of the said steel plate,
Zinc-based electroplated steel sheet. According to any one of claims 1 to 6, The average adhesion amount of the zinc-based electroplating layer is in the range of 5g / ㎡ to 40g / ㎡,
Zinc-based electroplated steel sheet. The zinc-based electroplating layer according to any one of claims 1 to 7,
5 mass%-20 mass% of any one or more addition elements selected from the group which consists of Fe, Ni, and Co;
Containing the remaining Zn and impurities,
Zinc-based electroplated steel sheet. The density of the plated particle whose particle diameter in the said rough part A is 0.3 micrometer or more is 10 <^10> / m <2>,
Zinc-based electroplated steel sheet. The zinc-based electroplating layer according to any one of claims 1 to 7, wherein the zinc-based electroplating layer is made of Zn,
In the surface layer of the zinc-based electroplating layer, the hexagonal laminate assembly crystal is included,
Zinc-based electroplated steel sheet. The zinc-based electroplated steel sheet according to any one of claims 1 to 10, further comprising a translucent organic resin coating layer on a surface of the zinc-based electroplating layer.

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