JP2001254195A - Highly corrosion-resistant composite electroplated steel sheet and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost highly corrosion-resistant electroplated steel sheet withstanding the severe environment even with a thin coating weight, not causing the deterioration of formability and spot weldability and excellent in bare corrosion resistance, flaw corrosion resistance after being coated, end- face corrosion resistance, etc., and its manufacturing method. SOLUTION: This composite electroplated steel sheet has a composite electroplating layer wherein the oxide grains each with a corrosion inhibitor consisting of at least one kind of organic compound selected from alkynes, alkynols, phenols, amines or their salts, thio compounds, heterocyclic compounds and aromatic carboxylic compounds or their salts adsorbed thereon are dispersed and containing 0.001-20 mass % C on one or both sides of the bare steel sheet or plated steel sheet. Otherwise, the composite electroplated steel sheet has a composite electroplating layer wherein the microcapsules encapsulating the corrosion inhibitor are dispersed and containing 0.001-20 mass % C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a composite zinc-based material which exhibits excellent corrosion resistance, formability and weldability in an unpainted or coated state, and is suitable as a rustproof steel sheet for automobiles, a material for home electric appliances, a building material and the like. The present invention relates to an electroplated steel sheet and a method for manufacturing the same.

[0002]

2. Description of the Related Art Various surface-treated steel sheets have been used in the fields of automobiles, home electric appliances, building materials, and the like.
There is a growing demand for improved rust-prevention performance of these surface-treated steel sheets. For example, in the case of surface-treated steel sheets for automobiles, the goal is to achieve 10 years of corrosion resistance and 5 years of external rust resistance in salt-damaged areas. High corrosion resistance is required. Incidentally, as a conventional rust-preventive steel sheet, a surface-treated steel sheet plated with zinc as a main component was generally used, but such a rust-preventive plated steel sheet has a sacrificial anti-corrosion effect that zinc has as its basic corrosion resistance. Therefore, it could not be said that it had sufficient anticorrosion performance under severe corrosive environment in winter in a cold region where rock salt was sprayed to prevent road freezing.

[0003] In other words, zinc alone is sufficient in terms of sacrificial corrosion protection of a steel sheet because zinc has a sufficiently low electrochemical potential as compared with a steel sheet base, but on the contrary, under conditions where salt exists, There is a problem that the dissolution rate of zinc is very fast, and the rust-preventing effect of the steel sheet cannot be maintained for a long period of time. Therefore, in order to improve this, Zn-
Zn-based alloy-plated steel sheets plated with an Fe alloy or a Zn-Ni alloy have come to be used. This alloy plating film has the property that its potential shifts preciously when corrosion starts, which reduces the potential difference from the base steel plate and suppresses the flow of severe corrosion current, thus achieving a long anti-corrosion life You can do it.

[0004] However, the Zn-Fe alloy electroplated material has a disadvantage that red rust is generated when the Fe component in the film is corroded, whereas the Ni in the film remains in a metal state in the Zn-Ni alloy electroplated material. Therefore, when the corrosion progresses to some extent, the potential relationship with the base steel sheet is reversed, and conversely, there is a problem that pitting corrosion of the base steel sheet is promoted. On the other hand, recently, a multi-layer plated steel sheet has been proposed in which the corrosion resistance is further improved by forming two rust-proof plated layers (Japanese Patent Application Laid-Open No. 60-215789, Japanese Patent Publication No. 58-1983).
No. 15554). However, considering the product performance required by consumers in recent years, the following problems have been pointed out in these multi-layer plated steel sheets.

That is, the multi-layer plated steel sheet disclosed in Japanese Patent Application Laid-Open No. 60-215789 has an adhesion amount of 10 to 30.
0 g / m ² Zn plating layer as a lower layer, Ni and / or C
o, a total of 15 to 30% by weight, and a coating amount of 1 to 20 g / m ² of a Zn-based alloy plating layer disposed on an upper layer. In order to exert the above, it is necessary to increase the adhesion amount of the lower Zn plating layer, which causes problems in workability, corrosion resistance after processing, spot weldability, and the like. Further, this multi-layer plated steel sheet is disadvantageous in cost because the upper Zn-based alloy plating layer contains a lot of expensive Ni and Co.

On the other hand, the multi-layer plated steel sheet described in Japanese Patent Publication No. 58-15554 is provided with an Fe-based flash plating as an upper layer for the purpose of improving phosphate conversion treatment properties and electrodeposition coating properties. It aims at indirectly increasing corrosion resistance by the effect of improving coating film adhesion. However, such a multi-layer plated steel sheet does not lead to improvement in bare corrosion resistance, and the degree of improvement in corrosion resistance after painting is only slight, and the corrosion resistance is basically the characteristics and adhesion amount of the underlying Zn-based plating layer. Depended largely on. In addition, Japanese Patent Application Laid-Open
The organic composite plated steel sheet described in Japanese Patent No. 70794 is aimed at improving corrosion resistance by directly dissolving a corrosion inhibitor in a plating bath and electrolyzing the corrosion inhibitor to thereby improve the corrosion resistance. There is a limit to the amount incorporated into the material, and the proportion of the corrosion inhibitor that decomposes during the electrodeposition process is relatively large, so that the improvement in corrosion resistance is limited.

[0007]

SUMMARY OF THE INVENTION
The object of the present invention is to provide a thin coating that does not cause deterioration in moldability or spot weldability, but also withstands a severe corrosive environment, bare corrosion resistance, scratch resistance after painting, end face corrosion resistance, etc. An object of the present invention is to provide a highly corrosion-resistant composite electroplated steel sheet which is sufficiently excellent and inexpensive, and a method for producing the same.

[0008]

Means for Solving the Problems The present inventors have found that the above problems can be effectively solved by dispersing a corrosion inhibitor (inhibitor) in a plating layer, and completed the present invention based on the solution. The gist of this is as follows. (1) On one or both sides of bare steel sheet or plated steel sheet,
Adsorbs a corrosion inhibitor comprising at least one organic compound selected from alkynes, alkynols, phenols, amines or salts thereof, thio compounds, heterocyclic compounds, and aromatic carboxylic acid compounds or salts thereof. Oxide particles are dispersed and the C content is 0.001-2.
A composite electroplated steel sheet having a composite electroplating layer of 0% by mass. (2) The oxide particles are composed of SiO ₂ , Al ₂ O ₃ , Zr
The composite electroplated steel sheet according to (1), wherein the composite electroplated steel sheet is made of one or more of O ₂ and TiO ₂ .

(3) In producing the composite electroplated steel sheet according to (1) or (2), the content of the corrosion inhibitor is 0.001 to 100 g / L, and the content of the oxide particles is A method for producing a composite electroplated steel sheet, comprising using a plating bath of 0.001 to 100 g / L. (4) On one or both sides of bare steel sheet or plated steel sheet,
A corrosion inhibitor comprising at least one organic compound selected from alkynes, alkynols, phenols, amines or salts thereof, thio compounds, heterocyclic compounds, and aromatic carboxylic acid compounds or salts thereof The microcapsules are dispersed and the C content is 0.001 to
A composite electroplated steel sheet having a composite electroplating layer of 20% by mass.

(5) The oxide particles are made of SiO ₂ , Al
The composite electroplated steel sheet according to the above (4), comprising one or more of ₂ O ₃ , ZrO ₂ , and TiO ₂ or an organic polymer having a film forming ability. (6) In producing the composite electroplated steel sheet according to (4) or (5), a plating bath in which the content of the microcapsules containing the corrosion inhibitor is 0.001 to 100 g / L is used. A method for producing a composite electroplated steel sheet.

(7) The composite electroplating layer is made of only Zn, or Co, Mn, Cr, Sn, Sb, P
b, Ni, Mo, Fe, Mg, or Si, and further contains one or more of them, and the amount of adhesion per one side is 10 mg /
wherein which is a ^{m 2 ~200g / m 2 (1} ), (2), (4), the composite electroplated steel sheet according to any one of (5). (8) When a plated steel sheet is used as the base, the base plating layer is made of one or two of Zn and Al, or Co, Mn, Cr, Sn, Sb, Pb, Ni, M
(1), (2), wherein at least one of o, Fe, Mg, and Si is further contained.
(4) The composite electroplated steel sheet according to any one of (5) and (7).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION By dispersing a corrosion inhibitor in zinc-based plating, the corrosion resistance has been dramatically improved. The most important part of the present invention is how to disperse the corrosion inhibitor. Even if the corrosion inhibitor is simply dissolved in the plating bath, the amount incorporated into the plating is limited, and the ratio of the corrosion inhibitor that decomposes during the electrodeposition process is relatively large, so that the corrosion resistance can be improved. Is limited. Therefore, in the present invention, by using oxide particles or microcapsules, the amount of the corrosion inhibitor taken in during plating is dramatically improved. That is, before being added to the plating bath, the corrosion inhibitor is adsorbed to the oxide particles in advance, as schematically shown in FIG. 1, or the corrosion inhibitor is micro-adsorbed, as schematically shown in FIG. By wrapping in a capsule and adding to the plating bath, it can be efficiently dispersed in the plating layer. Reference numeral 1 denotes a steel plate, and reference numeral 2 denotes Zn-based electroplating.

The corrosion-inhibiting organic compound (organic inhibitor) used in the present invention acts as a corrosion inhibitor in the course of corroding the plated material in a corrosive environment. When the content ratio and the amount of the plating film layer are within the specific ranges, a remarkable effect of improving corrosion resistance is exhibited, and it is possible to secure high corrosion resistance that surpasses conventional multi-layer plated steel sheets. Moreover, such a plated steel sheet can be sufficiently satisfied in terms of formability and spot weldability. The content (eutectoid content) of the corrosion-inhibiting organic compound in the plating layer corresponds to the C (carbon) content (eutectoid content) in the plating film layer.
It can be accurately grasped by the quantity.

In the present invention, the corrosion inhibiting organic compound is at least one selected from alkynes, alkynols, phenols, amines or salts thereof, thio compounds, heterocyclic compounds, and aromatic carboxylic acid compounds or salts thereof. One compound is used. Also, C (carbon)
By having a composite zinc-based plating film layer having a content of 0.001 to 20% by mass and preferably an adhesion amount of 10 mg / m ^{2 to} 200 g / m ² , excellent bare corrosion resistance, scratch resistance after painting, and the like. It has both end face corrosion resistance, moldability and spot weldability.

The present invention relates to an electroplating layer containing a corrosion-inhibiting organic compound (corrosion-inhibiting organic compound such as alkynes) on one or both sides of a bare steel sheet or a zinc-based plated steel sheet (corrosion-inhibiting organic compound-containing flash plating layer). Although the present invention relates to a composite plated steel sheet provided with, the kind of the steel sheet as a base material is not particularly limited, and any of a normal steel sheet and a cold-rolled steel sheet for an automobile body may have a corresponding effect. Can be secured. In addition, when the material steel sheet provided for forming the corrosion-inhibiting organic compound-containing composite plating film layer is a zinc-based plated steel sheet, the type of the zinc-based plating (zinc plating or zinc alloy plating) is not limited, and a known type is used. Any hot-dip or electrogalvanized steel sheet may be used.

Also, when the material steel sheet used for forming the corrosion-inhibiting organic compound-containing composite plating film layer is an aluminum-based plating steel sheet, the type of aluminum-based plating (aluminum plating or aluminum alloy plating) is not similarly limited. Absent. In any of the above plating layers, Co, Mn, Cr,
1 of Sn, Sb, Pb, Ni, Mo, Fe, Mg, Si
Species or two or more species may be included. In addition, a plating bath composition for forming a composite zinc-based electroplating film layer,
The electrolysis conditions are as follows, for example, in the case of zinc plating in which a corrosion inhibiting organic compound is eutectoid.

[0017] [I] Plating bath composition _{ZnSO 4 · 7H 2 O: 50~400g} / L, Na 2 SO 4: 10~200g / L, H 2 SO 4: 5~50g / L, the oxide particles: 0. 001 to 100 g / L, corrosion inhibiting organic compound: 0.001 to 100 g / L, pH: 0 to 4

[II] Electrolysis conditions Bath temperature: 40 to 65 ° C., current density: 40 to 150 A / dm ² , liquid flow rate: 0.5 to 3 m / sec, and zinc-based alloy plating for co-depositing a corrosion inhibiting organic compound In the case of, the alloying element is added in the same plating bath as above in the form of sulfates, acetates, carbonates, molybdates, hypophosphites, organometallic salts, or these metals are added in advance. What is necessary is just to use the plating bath which added so that it might become a target composition in the state which melt | dissolved the element. Of course, the above bath composition is merely an example, and is not limited to the above bath composition as long as it is a zinc-based electroplating bath containing 0.001 to 100 g / L of the corrosion inhibiting organic compound and the oxide particles, respectively.

The corrosion inhibiting organic compound applied to the present invention is one of alkynes, alkynols, phenols, amines or salts thereof, thio compounds, heterocyclic compounds, and aromatic carboxylic acid compounds or salts thereof. That is all. Among these, alkynes are organic compounds containing a carbon-carbon triple bond, such as pentyne,
Hexin, heptin, octin and the like can be mentioned. The alkynols are organic compounds having one or more hydroxyl groups in the alkynes, and include, for example, propargyl alcohol, 1-hexyn-3-ol, 1-heptin-3-ol, and the like.

A phenol is an organic compound having one or more hydroxyl groups bonded to a benzene ring, and examples thereof include phenol, catechol and cresol. Amines are organic compounds containing one or more nitrogen atoms in the molecule, and include both aliphatic and aromatic compounds. Examples of such amines include octylamine, nonylamine, decylamine, laurylamine, tridecylamine, and cetylamine. The thio compound means an organic compound containing one or more sulfur atoms in the molecule. Examples of such a thio compound include decyl mercaptan, cetyl mercaptan, and thiourea.

The term "heterocyclic compound" means an organic compound in which an atom other than carbon is contained as an element of the ring in a cyclic molecule.
Examples thereof include pyridine, benzothiazole, benzotriazole, quinoline, indole, tannic acid, catechin, and flavonoid. Examples of the aromatic carboxylic acid include benzoic acid, salicylic acid, sulfylic acid, and naphthalene carboxylic acid. Note that salts of amines and carboxylic acids can be used, and even in this case, the same effect can be obtained.

It has already been mentioned that these compounds are eutectoid in the plating film layer formed at the time of electrodeposition and act as a corrosion inhibitor during the corrosion process, so that they exhibit a remarkable effect of improving corrosion resistance. As described above, corrosion resistance that is difficult to obtain with the conventional two-layer plating film is secured. In addition, since a part of the organic compound is taken into the plated metal matrix as C (carbon), the mechanical properties and the electrical properties are improved, so that good moldability and spot weldability can be provided.

In the surface-treated steel sheet according to the present invention, C
Elements constituting a corrosion inhibiting organic compound other than, for example, N,
This does not prevent O, S, and the like from being present in the plating film, and the desired effect can be sufficiently ensured by this. However, when the amount of the corrosion inhibiting organic compound added to the plating bath is less than 0.001 g / L, there is almost no eutectoid in the plating film layer, and the C content is less than 0.001% by mass. Therefore, there is no effect in improving the corrosion resistance.

On the other hand, when the amount of the corrosion inhibiting organic compound is 100 g
If it exceeds / L, it becomes difficult to add it to the plating bath from the viewpoint of solubility, and the surface properties may be reduced depending on the type of the corrosion inhibiting organic compound. Accordingly, the content of the corrosion inhibiting organic compound in the plating bath is limited to 0.001 to 100 g / L, but is preferably adjusted to 0.05 to 50 g / L. More preferably, it is 0.1 to 20 g / L for alkynes, alkynols and phenols, and 0.1 to 20 g / L for amines or salts thereof.
It is recommended to adjust the amount to 0.2 to 20 g / L for thio compounds, to 1.5 to 20 g / L for heterocyclic compounds, and to 3 to 15 g / L for aromatic carboxylic acid compounds or salts thereof.

When the amount of the oxide particles added to the plating bath is less than 0.001 g / L, the effect (increase in the amount of C-eutectoid) is almost negligible. Agglomeration tends to cause precipitation. Therefore, the content of the oxide particles in the plating bath was limited to 0.001 to 100 g / L. On the other hand, if the amount of the microcapsules added to the plating bath is less than 0.001 g / L, including the contained corrosion-inhibiting organic compound, the effect (increase in the amount of C-eutectoid) is almost negligible, and 100 g / l. If it exceeds L, the microcapsules are likely to aggregate and precipitate. Therefore, the content of the microcapsules containing the corrosion inhibiting organic compound in the plating bath is preferably 0.001 to 100 g / L.

The material of the microcapsules is SiO
_Two, Al_TwoO_Three, ZrO_Two, TiO _TwoAny one of
Or two or more, or ethyl cellulose, amino tree
Film type such as fat, vinylidene chloride resin and polyethylene
It is preferably an organic polymer capable of synthesizing. Also,
The thickness of the microcapsule is preferably 1 nm to 1 μm,
Is preferably 1 to 50 nm. If the film thickness exceeds 1 μm,
If SiO_TwoIn this case, the aggregation of particles is likely to occur.
The properties of the film material tend to be noticeable and the plating properties deteriorate
You. Conversely, if the thickness is less than 1 nm, the coatability deteriorates.
To suppress the dissolution of the corrosion-inhibiting organic compounds contained therein
Effect is reduced.

By using a plating bath to which oxide particles adsorbing such a corrosion-inhibiting organic compound or microcapsules containing the corrosion-inhibiting organic compound is added, the amount of C-eutectoid (C content) on the steel sheet surface is reduced. A composite electroplating film layer of 0.001 to 20% by mass can be formed. To confirm the C content in the composite electroplating film layer, only the composite plating film layer is mechanically peeled from the base steel sheet. Quantification by a combustion method (gas analysis) can be easily performed.

Here, the corrosion inhibiting organic compound according to the present invention is used.
C content obtained in the additive-added plating bath is 0.001 to 2
The adhesion amount of the composite electroplating film layer of 0 mass% is 10 mg /
m^Two~ 200g / m^TwoIt is preferably adjusted to. This
This means that the adhesion amount is 10 mg / m ^TwoIf less than the desired effect
Fruit is not fully exhibited, while 200g / m^TwoAdhesion amount
The effect can be secured enough when it reaches
Because they just get together. More preferably, 1 to
200g / m^TwoIt is preferably adjusted to.

[0029]

EXAMPLES The effects of the present invention will be described more specifically with reference to examples. (Example 1) A cold rolled steel sheet was used as a plating base material, and Table 1 was used.
Using a plating bath obtained by adding various corrosion-inhibiting organic compounds and oxide particles to the basic composition shown in (1) (with no addition of the corrosion-inhibiting organic compound and oxide particles in the comparative example), the electroplating conditions were also shown in Table 1. Various zinc-based electroplated steel sheets were prepared. Table 2 shows the plating film composition of the plated steel sheet thus obtained, together with the types of the corrosion-inhibiting organic compound and oxide particles added to and contained in the plating bath, and the contents in the plating bath. Table 3 shows the results when microcapsules were used. For these plated steel sheets, "bare corrosion resistance", "corrosion resistance after coating", "edge corrosion resistance after coating", "coating film adhesion",
"Formability" and "spot weldability" were evaluated, and the evaluation results are also shown in Tables 2 and 3. The above-mentioned "bare corrosion resistance", "corrosion resistance after coating", "corrosion resistance after coating", "coating film adhesion", "formability" and "spot weldability" are as follows. evaluated.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

(A) Bare Corrosion Resistance First, a 70 mm × 150 mm test piece was cut out from a plated steel sheet, and the end face and the back face of this unprocessed flat plate were sealed, and a salt spray test (SST) using 5% NaCl was performed for 35 days.
The coating was performed at 24 ° C. for 24 hours, and the bare corrosion resistance was evaluated in the following stages according to the area ratio of white rust and red rust on the plating surface. ：: 1% or less for both white rust and red rust, ○: 10% or less for white rust, 1% or less for red rust, Δ: 50% or more for white rust, 1% or less for red rust, ×: 50% or more for white rust, 1 to 30% for red rust , Xx: white rust 50% or more, red rust 30% or more

(B) Corrosion resistance of flaws after coating First, a 70 mm × 150 mm test piece was cut out from a plated steel sheet, and this unprocessed flat plate was degreased with FC4336.
(Product name: Nippon Parkerizing Co., Ltd.), PZT
After surface conditioning with (trade name: Nippon Parkerizing), phosphate treatment was performed using PB-L3080 (trade name: Nippon Parkerizing), and then U-80.
(Product name: Nippon Paint Co., Ltd.) was applied with a cationic electrodeposition coating having a thickness of 20 ± 1 μm and baked at 175 ° C. for 25 minutes. Then, afterwards, the intermediate coating (4
0 μm), baked, overcoated with a melamine / polyester paint (40 μm), and baked to prepare a sample.

Next, a cross-cut reaching the steel plate base was made on the evaluation surface (painted surface) side of the sample with a cutter knife, and a composite corrosion test was performed under the following cycle settings. Salt spray (5% NaCl, 35 ° C., 7 hours) → dry (5
0 ° C, 2 hours) → Wet (RH 85%, 50 ° C, 15 hours) For the evaluation of the flaw corrosion resistance, after performing the above corrosion cycle test for 30 cycles, the blister degree of the cross cut part is classified into the following stages. I went. ◎: Blister width <0.5 mm, ：: Blister width <1.0 mm, Δ: Blister width <2.0 mm, ×: Blister width <3.0 mm, XX: Blister width ≧ 3.0 mm

(C) Corrosion resistance of the end face after coating First, the burrs on the end face of the test piece from the plated steel sheet had a thickness of 10%.
%, The punch of the die was adjusted by adjusting the clearance of the mold, and the punched test piece was subjected to the same electrodeposition coating, intermediate coating, and top coating as described above to prepare a sample. And
This test piece was subjected to the same corrosion cycle test as described above.
The end face corrosion resistance was evaluated by performing the corrosion cycle test for 60 cycles and then dividing the area ratio of red rust occurrence on the end face into the following stages. ：: No red rust occurred, ○: Red rust occurred 5% or less, Δ: Red rust occurred 10% or less, ×: Red rust occurred 30% or less, XX: Red rust occurred more than 30%

(D) Coating film adhesion The coated steel sheet prepared by the method described above
It was immersed for 0 days, a grid of 2 mm × 100 squares was put, and the coating film peeling ratio was measured by taping. The coating film adhesion was evaluated in the following stages. ：: coating film peeling rate 0%, ○: coating film peeling rate 5% or less, Δ: coating film peeling rate 5 to 20%, ×: coating film peeling rate 20 to 50%, XX: coating film peeling rate 50% that's all

(E) Formability (a) Workability A 90 mmφ disc-shaped blank is sampled from a plated steel sheet, and this is deep-drawn into a cylindrical shape having a diameter of 50 mmφ and a depth of 28 mm, and the side wall surface thereof is formed. A test was conducted in which the plating film was peeled off with an adhesive tape, and the amount of the peeling was visually inspected and evaluated. The workability was evaluated by dividing the peeling amount into the following stages. 5: No peeling at all, 4: Less than 10% of the tape area to which the peeled piece adhered, 3: Less than 30% of the tape area to which the peeled piece adhered, 2: The tape area to which the peeled piece was adhered Less than 50%, 1: Attached to the entire surface of the tape

(B) Formability Regarding the formability, the presence or absence of base material fracture during “deep drawing forming” when performing the above-described workability evaluation (Yes: ○, No:
X). The results of the evaluation are shown as ○: no base material break, ×: base material break.

(F) Spot Weldability Specimens were sampled from plated steel sheets and evaluated by the number of possible continuous spot welding spots. The continuous spot welding conditions were as follows. Current: 10000A, Pressure: 200kgf, Energizing time: 12 cycles (at 60Hz), Electrode shape: Dome, Welding method: "40 points after continuous 20 point welding at 1 point / 2 seconds"
A cycle of "pause for more than one second" is repeated. Three shear test pieces are collected every 100 points, and the nugget diameter is measured after the tensile test.

The evaluation of spot weldability was 1500 points or more, and was indicated in the next stage. ：: 2,000 points or more, ： １: 1500 points or more, Δ: less than 1500 points, ×: less than 1000 points As is clear from the results shown in Tables 2 and 3, any of the composite galvanized steel sheets according to the present invention was used. Also excellent corrosion resistance after coating, corrosion resistance of the end face after coating, coating adhesion,
It turns out that it has both moldability and weldability.

[0042]

As described above, according to the present invention, not only the excellent corrosion resistance after painting than the conventional surface-treated steel sheet, but also the weldability and forming process which are easy for the user to use. Thus, it is possible to stably provide a surface-treated steel sheet having excellent properties, and it is possible to greatly contribute to improving the performance of automobiles, home electric appliances, building materials, and the like.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a dispersion form of a corrosion-inhibiting organic compound (organic inhibitor) by adsorption to oxide particles in a plating layer of the present invention.

FIG. 2 is a diagram schematically showing a dispersion form of a corrosion-inhibiting organic compound (organic inhibitor) by inclusion in a microcapsule in a plating layer of the present invention.

[Explanation of symbols]

 1 Steel plate 2 Zn-based electroplating

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K023 AA15 AA20 AB29 AB50 BA06 CA09 CB01 CB05 CB07 CB11 CB21 CB28 DA02 DA06 DA07 DA08 4K024 AA01 AA05 AA17 AA18 AA19 AA20 AB01 AB02 AB06 AB12 BA03 BB02 GA03 BC01 GA04

Claims (8)

[Claims] 1. An alkyne, an alkynol, a phenol, or the like, on one or both sides of a bare steel sheet or a plated steel sheet.
Oxide particles adsorbing a corrosion inhibitor comprising at least one organic compound selected from amines or salts thereof, thio compounds, heterocyclic compounds, and aromatic carboxylic acid compounds or salts thereof are dispersed; Content 0.0
A composite electroplated steel sheet having a composite electroplating layer in an amount of from 0.01 to 20% by mass. 2. The method according to claim 1, wherein the oxide particles are made of SiO ₂ , Al ₂ O.
_3, the composite electroplated steel sheet according to claim 1, characterized in that it consists of ZrO _2, 1 kind of TiO ₂ or more. 3. The production of the composite electroplated steel sheet according to claim 1 or 2, wherein the content of the corrosion inhibitor is 0.001 to 100 g / L, and the content of the oxide particles is 0.001 to 100 g / L. A method for producing a composite electroplated steel sheet, comprising using a plating bath of 100 g / L. 4. An alkyne, alkynol, phenol, or alkyne, alkynol,
Microcapsules containing a corrosion inhibitor comprising at least one organic compound selected from amines or salts thereof, thio compounds, heterocyclic compounds, and aromatic carboxylic acid compounds or salts thereof are dispersed and have a C content of Is 0.
A composite electroplated steel sheet having a composite electroplating layer of 001 to 20% by mass. 5. The method according to claim 1, wherein the oxide particles are SiO ₂ , Al ₂ O.
_3, the composite electroplated steel sheet according to claim 4, characterized in that it consists of an organic polymer having one or more or the film forming ability of ZrO _2, TiO _2. 6. The production of the composite electroplated steel sheet according to claim 4 or 5, wherein the content of the microcapsules containing the corrosion inhibitor is 0.001 to 100 g / L.
A method for producing a composite electroplated steel sheet, comprising using a plating bath that is: 7. The composite electroplating layer is composed of only Zn, or is composed of Co, Mn, Cr, Sn, Sb, Pb,
One or more of Ni, Mo, Fe, Mg, and Si are further contained, and the adhesion amount per side is 10 mg / m2.
^{2. The} composition according to claim 1, wherein the weight is ^{2 to} 200 g / m ² .
2. The composite electroplated steel sheet according to any one of 2, 4, and 5. 8. When a plated steel sheet is used as a base, the base plating layer is made of one or two of Zn and Al, or is composed of Co, Mn, Cr, Sn, Sb, Pb,
3. The composition according to claim 1, further comprising one or more of Ni, Mo, Fe, Mg, and Si.
The composite electroplated steel sheet according to any one of 4, 5, and 7.