KR100920596B1 - Zinc or Zinc Alloy Coated Steel Sheets with an Excellent Drawability, Adhesiveness and Phosphatability and Method for Manufacturing the Same - Google Patents

Abstract

The present invention relates to a zinc or zinc-based alloy plated steel sheet used as a steel sheet for automobiles and a method for manufacturing the same, and to provide a zinc or zinc-based alloy plated steel sheet excellent in workability, adhesiveness and chemical conversion treatment, and a method of manufacturing the same. , Its purpose is.

In the present invention, a nickel (Ni) or nickel alloy plating layer having an adhesion amount of 1 to 1000 mg / m ² is formed on the zinc plating layer or a zinc-based alloy plating layer, and an adhesion amount of 10 to 2000 mg / m ² is formed on the lower layer coating as an upper layer coating. Phosphate coating A zinc or zinc-based alloy plated steel sheet excellent in workability, adhesiveness, and chemical conversion treatment formed is provided.

According to the present invention, it is possible to provide a zinc or zinc-based alloy plated steel sheet excellent in workability, adhesion and chemical conversion treatment.

Processability, Nickel, Chemical Treatment, Phosphate Coating

Description

Zinc or Zinc Alloy Coated Steel Sheets with an Excellent Drawability, Adhesiveness and Phosphatability and Method for Manufacturing the Same}

The present invention relates to a zinc or zinc-based alloy plated steel sheet used in automotive steel plates and the like, and more particularly, to a zinc or zinc-based alloy plated steel sheet excellent in workability, adhesiveness and chemical conversion treatment, and a method of manufacturing the same. It is about.

Zinc or zinc-based alloy plated steel sheet has a beautiful surface appearance and sacrificial action against iron, which is a steel sheet. .

However, due to the rough and brittle plating layer, the contact area with the die is wide and easy to be adhered to during processing, which causes cracking of the steel sheet itself due to high frictional loads when press-molding the coated steel sheet. It will act as a factor to lower the.

On the other hand, an adhesive is used to bond the inner and outer plates of a steel sheet for automobiles, and this adhesive prevents noise while driving the vehicle body, improves dent resistance of the outer plate, and prevents penetration of contaminants such as water or salt into the hamming part. This protects the car body from corrosion.

Therefore, if there is a component that adversely affects the adhesion of foreign substances or adhesives on the surface of the steel sheet may increase the noise of the car, as well as cause serious problems in stability in long-term use.

In addition, automotive companies press-form steel sheets into desired shapes, undergo degreasing and chemical conversion, and then perform electrodeposition coating. Since zinc and zinc-based alloy-plated steel sheets have a base layer compared to iron, crystal grains are formed during chemical conversion. This coarse coarse hopitite crystal is formed, which makes it easy to form electrodeposition coating defects such as pinholes during electrodeposition coating. Therefore, it is disadvantageous in terms of corrosion resistance after painting.

In order to improve the above problems, the alloying hot-dip galvanized steel sheet (hereinafter referred to as "GA steel sheet") or zinc-iron (nickel) alloy electroplating steel sheet contains iron or zinc by electroplating to contain 95 wt.% Or more of iron or phosphorus. (Fe-Zn), iron-manganese (Fe-Mn) or in-iron alloy to 3000 ~ 5000mg / m ² thin-plated flash (flash) steel sheet, such as (P-Fe) been used, the cost during steel sheet production Due to the high price, automakers have suspended the use of flash steel for cost reduction.

In addition, the coating or resin phosphate treatment on the zinc-based galvanized steel sheet to improve the processability and adhesion, but because the resin coating is very low melting point and no conductivity, the traces of the electrode remains intact during welding is transferred to defects The use was discontinued due to the phenomenon.

On the other hand, a method of manufacturing a phosphate-based automotive lubricating steel sheet excellent in workability by coating a phosphate solution containing nickel, manganese, zinc binary or ternary metal ions of low cost and excellent workability on a zinc-based galvanized steel sheet Known.

However, in the above method, since phosphoric acid is a weak acid, it is impossible to reduce the free acid in a solution by more than a certain limit, which causes a large amount of free phosphoric acid to remain in the coating, which reduces the adhesion with the adhesive and has a very poor adhesiveness. Have.

In addition, zinc or zinc-based galvanized steel sheet is also disadvantageous in chemical conversion treatment and electrodeposition coating properties because the plating layer is electrochemically compared.

The present invention has been made in view of the above problems, and an object thereof is to provide a zinc or zinc-based alloy plated steel sheet excellent in workability, adhesion and chemical conversion treatment.

Another object of the present invention is to provide a method for producing a zinc or zinc-based alloy plated steel sheet excellent in workability, adhesion and chemical conversion treatment.

Hereinafter, the present invention will be described.

In the present invention, a nickel (Ni) or nickel alloy plating layer is formed on the zinc plating layer or the zinc-based alloy plating layer of a zinc or zinc-based alloy plating steel sheet having a zinc plating layer or a zinc-based alloy plating layer, and an upper layer is formed on the lower coating. A phosphate film is formed as a film,

The adhesion amount of the lower layer is 1 ~ 1000mg / m ² , the adhesion amount of the upper layer is 10 ~ 2000mg / m ² ,

The phosphate coating is a coating composition comprising 1 to 30% by weight of hypophosphorous acid, 0.1 to 10% by weight of manganese, zinc oxide and the balance or a coating composition to which 0.01 to 5% by weight of a polyvinyl compound is additionally added. It is formed by apply | coating on a lower layer film, and drying,

The zinc oxide in the coating composition is included in an amount such that the amount of NaOH consumed for neutralization titration is 10.0 ml or less when neutralizing titration of 50 ml of the coating composition with 0.1 N NaOH, and the content of the free acid in the coating composition. When 50 ml of silver coating composition is neutralized with 0.1 N NaOH, the amount of NaOH consumed in the neutralization titration is controlled to be 10.0 ml or less. It relates to an interlocking alloy plated steel sheet.

In addition, the present invention is a lower layer consisting of a nickel (Ni) or nickel alloy layer having an adhesion amount of 1 ~ 1000mg / m ² on the zinc plating layer or zinc-based alloy plating layer of the zinc or zinc-based alloy plated steel sheet having a zinc plating layer or zinc-based alloy plating layer. Forming a film; And

1-30% by weight of hypophosphorous acid, 0.1-10% by weight of manganese, zinc oxide and the remainder of the coating composition or 0.01 to 5% by weight of the polyvinyl compound is further added thereto, the zinc oxide is In the case of neutralizing titration of 50 ml of the coating composition with 0.1 N NaOH, the amount of NaOH consumed in the neutralization titration is 10.0 ml or less, and the content of the free acid in the coating composition is 50 ml of the coating composition. In the case of neutralizing titration with 0.1 N NaOH, prepare a coating composition controlled to the amount of NaOH consumed in the neutralization titration to 10.0 ml or less, and apply the coating layer on the lower layer so that the coating amount is 10-2000 mg / m2. It relates to a process for producing a zinc or zinc-based alloy plated steel sheet excellent in workability, adhesion and chemical conversion treatment comprising the step of forming an upper layer by drying.

According to the present invention, by forming a nickel or nickel alloy plating layer as a lower coating on a zinc or zinc-based alloy plated steel sheet, and forming a phosphate coating thereon, a zinc or zinc-based alloy plated steel sheet excellent in workability, adhesion and chemical conversion treatment Can provide.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

Examples of the zinc or zinc-based alloy plated steel sheet having a zinc plated layer or a zinc-based alloy plated layer in the present invention include hot-dip galvanized steel sheets, electro-galvanized steel sheets, and zinc-based alloy plated steel sheets.

Examples of the zinc-based alloy plated steel sheet include zinc-iron (cobalt and nickel) alloy electroplated steel sheet, zinc-aluminum alloy plated steel sheet, zinc-magnesium alloy plated steel sheet, and alloyed hot dip galvanized steel sheet (GA steel sheet).

The content of Ni in the nickel alloy plating layer is not particularly limited, but considering the workability and chemical conversion treatment, the content of Ni in the nickel alloy plating layer is preferably 90% by weight or more.

When the Ni content in the nickel alloy plating layer is 90% by weight or more, it is advantageous for workability and promotes nucleation in the coating layer during chemical conversion, thereby making a fine chemical conversion coating film, thereby forming an electrodeposited coating film without defects.

When the nickel content in the nickel alloy plating layer is 90% or less, the stability of the solution is poor, the workability is poor, and the electrochemical nobility of the coating layer is low.

In the present invention, the upper layer is dissolved and removed in an alkali degreasing step performed in an automobile company.

On the other hand, the nickel and nickel-based alloy plating layer of the lower layer is combined with the zinc plating layer or the zinc-based alloy plating layer by an electrochemical reaction, so that it is not dissolved and removed by alkaline degreasing solution, thereby promoting nucleation during chemical conversion. Will be

Although the formation method of the said nickel (Ni) or nickel alloy plating layer is not specifically limited, It is preferable to form by the electroplating method.

The plating bath used for forming the lower layer film by the electroplating method is not particularly limited, and representative examples thereof include a sulfuric acid bath and a chloride bath.

It is preferable to limit the adhesion amount of the lower layer coating to the range of 1 to 1000 mg / m ² per single side, and more preferably, the adhesion amount is 10 to 500 mg / m ² .

The amount of adhesion can be controlled by the amount of current to give.

When the nickel or nickel alloy plating layer coating is coated on the zinc-based plating layer, the melting point and hardness are increased, resulting in very fine grains of the chemical conversion treatment film.

1 is a Ni-treated GA steel sheet and the plated Ni on the GA steel sheet by the amount of adhesion compared to the chemical conversion treatment, as shown in Figure 1 Ni-free GA steel sheet compared with the very coarse grain of the chemical conversion coating It can be seen that when the Ni film is present on the GA steel sheet, the grain becomes very fine, 5 microns or less.

In FIG. 1, the coating amount is measured by substituting a calibration curve prepared in advance after measuring the intensity value of Ni with a X-ray fluorescense spectrometer (XRF).

If the adhesion amount of the nickel or nickel alloy plating layer is less than 1mg / m ² can not be expected to improve the chemical conversion treatment, if it is more than 1000mg / m ² takes a long time to chemical conversion treatment, the coating amount of the chemical conversion coating is not secured, it is uneconomical.

Hereinafter, the phosphate film which is an upper film is demonstrated.

Phosphate coating has excellent lubricity when forming the steel sheet because the coating itself has lubricity. However, if free acid is present on the surface, the phosphate coating damages the bonding strength with the adhesive.

The phosphate coating is a coating composition comprising 1 to 30% by weight of hypophosphorous acid, 0.1 to 10% by weight of manganese, zinc oxide and the balance or a coating composition to which 0.01 to 5% by weight of a polyvinyl compound is additionally added. It is formed by apply | coating on a lower layer film, and drying,

The zinc oxide in the coating composition is included in an amount such that the amount of NaOH consumed for neutralization titration is 10.0 ml or less when neutralizing titration of 50 ml of the coating composition with 0.1 N NaOH, and the content of the free acid in the coating composition. In the case of neutralizing titration of 50 ml of silver coating composition with 0.1 N NaOH, the amount of NaOH consumed for neutralization titration is controlled to an amount of 10.0 ml or less.

The deposition amount of the phosphate film is preferably 10 to 2000 mg / m ² , and more preferably 100 to 1000 mg / m ² .

According to the present invention, when the coating composition is coated on a steel sheet and dried, a reaction of decomposing water molecules while drying and a coupling reaction between oxygen in the air and the coating occurs simultaneously.

Although oxygen is present in the form of a metal oxide in the phosphate coating, the exact bonding form and chemical formula of the oxide are not known. The composition of the phosphate coating except for oxygen and impurities is 40 to 60% by weight of phosphorus (P) and 30 to It is preferable that it consists of 50 weight% zinc (Zn) and 1-20 weight% manganese (Mn).

The phosphate coating may further contain 0.01 to 5% by weight of a polyvinyl compound.

If the phosphorus (P) component in the upper layer is 40% by weight or less, the friction properties deteriorate, and processability cannot be expected, and when a large amount of phosphoric acid is added to the solution to secure 60% by weight or more, a precipitate is formed in the solution, making it impossible to use. It becomes

If the zinc is 30% by weight or less, the free acid concentration in the solution is increased to increase the free acid in the coating, so that the adhesion is deteriorated, and when the zinc is 50% by weight or more, the hardness of the plating layer is lowered to inhibit workability.

 If the manganese is less than 1% by weight, the workability deteriorates and 20% by weight or more is required to add a large amount of manganese in the solution.

Coating composition of the present invention used to form a phosphate film, specifically, a phosphorus-zinc-manganese film or a film further containing a polyvinyl compound in the zinc-zinc alloy plated steel sheet. ) Comprises hypophosphorous acid, manganese, zinc oxide and the balance or by addition of a polyvinyl compound to it, the concentration of the free acid is controlled.

Further, waxes, lubricants and the like may be optionally added to the coating composition of the present invention as needed.

Of course, the coating composition of the present invention may include components that can be optionally added as needed in the art in addition to waxes and lubricants.

Hypophosphoric acid and manganese in the coating composition of the present invention as a factor that determines the processability of hypophosphorous acid in the composition 1-30% by weight, preferably 5-15% by weight, more preferably 5-10% by weight, and manganese 0.1 to 10% by weight, preferably 0.1 to 1% by weight, more preferably 0.1 to 0.5% by weight.

If the content of hypophosphorous acid is less than 1% by weight, the processability is lowered, and if it exceeds 30% by weight, solution management is difficult and the amount of zinc oxide to reduce the free acid concentration is very uneconomical.

In consideration of processability and economic efficiency, the hypophosphorous acid content is 1 to 30% by weight, preferably 5 to 15% by weight, more preferably 5 to 10% by weight.

If the manganese content is less than 0.1% by weight, the processability is poor, and if the manganese content is more than 10% by weight, it is difficult to completely dissolve manganese and it is uneconomical.

In consideration of processability and economical efficiency, the manganese content is 0.1 to 10% by weight, preferably 0.1 to 1% by weight, more preferably 0.1 to 0.5% by weight.

On the other hand, as a method of securing manganese in the coating composition, the metal manganese can be directly dissolved in the composition, and the amount of manganese carbonate, potassium permanganate, and the like can also be dissolved in the amount of manganese.

The polyvinyl compound is optionally added to improve the adhesion of the steel sheet, polyvinyl acetate (PVA), polyvinyl alcohol (PVAL), polyvinyl butyral (PVB), polyvinyl formal (PVF), poly Substances such as vinyl ether (PVE) fall into this category and one or two or more of them may be used in combination.

By adding 0.01 to 5% of the polyvinyl compound in the solution to form -OH groups in the coating, the adhesive strength can be greatly improved by strengthening the bonding force with the polar groups -C = O, -N-, and -O- of the adhesive. have.

When the polyvinyl compound is added at 0.01% or less, the adhesiveness is not improved. When the polyvinyl compound is added at 5% or more, the polyvinyl compound is uneconomical, as well as the amount of foaming in the solution, which greatly reduces workability and no longer improves the adhesiveness.

In consideration of adhesiveness, economical efficiency and workability, the polyvinyl compound content is 0.01 to 5% by weight, preferably 0.05 to 0.5% by weight, more preferably 0.05 to 0.1% by weight.

The zinc oxide is added to minimize the content of free acid in the composition. In the coating composition, zinc oxide is 10.0 ml of the amount of NaOH consumed in the neutralization titration when 50 ml of the coating composition is neutralized with 0.1 N NaOH. Or less, preferably in an amount of 8.3-8.8 ml.

Therefore, the concentration of the free acid in the coating composition according to the present invention is less than 10 ml, preferably 8.3-8.8 ml of the amount of 0.1 N NaOH consumed in the neutralization titration when 50 ml of the coating composition is neutralized with 0.1 N NaOH. The amount is controlled to be

In the present specification, for the sake of convenience, the content of the free acid in the coating composition is represented as an amount consumed when titrating with 0.1 N NaOH, but the present invention is not limited thereto, and includes the case where the same acid concentration is obtained by titration with another alkaline solution. Of course.

If the content of the free acid in 50 ml of the coating composition exceeds a concentration corresponding to 10 ml of 0.1 N NaOH, the adhesion of the phosphate coating, ie, the phosphorus-zinc-manganese coating, to the zinc or zinc-based alloy plated steel sheet is poor.

In addition, the lower the concentration of the free acid in the coating composition is more preferable, but the lower limit thereof is not limited. However, the coating composition and the coated steel sheet may be used when the content of the free acid in 50 ml of the coating composition is less than 8.3 ml of 0.1 N NaOH. Because of its lack of reactivity, the adhesion of the lubricating film is weakened and precipitates are formed in the solution.

Roughly, zinc oxide is used in the composition in a nearly saturated solubility so that the content of free acid in 50 ml of the coating composition is less than or equal to 10 ml of 0.1 N NaOH.

On the other hand, the addition of alcohol to the film-forming composition of the present invention has the advantage that the surface tension of the solution is increased and the spreadability and wettability is improved to obtain a uniform lubricating film without stains.

Thus, alcohol may optionally be added to the coating composition of the present invention as needed up to 5% by weight, preferably 2 to 4% by weight.

If the alcohol content exceeds 5% by weight, it is not preferable because the aging of the composition is promoted. The alcohol is optionally added as necessary, and the lower limit is not limited, but in order to exhibit sufficient surface tension increase effect due to the addition of alcohol, it is preferable to add 2% by weight or more.

Ethyl alcohol may be generally used as the alcohol.

When the phosphate film is formed on the plated steel sheet by using the coating composition prepared as described above, a phosphate film having excellent adhesion can be obtained.

According to the present invention, the coating composition of the present invention is coated on a nickel and nickel-based alloy plating layer, which is a lower layer, and dried to form a polyvinyl phosphate layer, specifically, a phosphorus-zinc-manganese layer or a phosphorus-zinc-manganese layer. The film to which the compound was added is formed.

The coating composition for forming the phosphate film, which is the upper layer film of the present invention, has a one-side coating amount of 10 to 2000 mg / m2, preferably 100 to 1000 mg / m2, more preferably on the nickel and nickel-based alloy plating layer, which is the lower layer. Apply 200-400mg / m 2.

If the coating amount is less than 10 mg / m 2, the workability, which is the original purpose of the lubricated steel sheet, is deteriorated. If the coating amount is more than 2000 mg / m 2, there is no effect of improving workability.

On the other hand, the coating is not limited to this, but for example, it can be carried out by using a roll coater or by spraying the composition on the steel sheet surface. In no case, however, should it be washed after coating. Coating can generally be carried out at room temperature. Although it does not specifically limit drying after coating, It is preferable to dry at 30-200 degreeC, and more preferable drying temperature is about 70-100 degreeC. If the steel sheet temperature is less than 30 ° C., the coating may not be completely dried. If it exceeds 200 ° C., it is uneconomical.

In consideration of drying properties, economical efficiency, and the like, the preferred drying temperature is 30 to 200 ° C, and the more preferable drying temperature is 70 to 100 ° C.

The upper and lower layers of the present invention may be formed on one side or both sides of the plated steel sheet.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example  One

The GA steel sheet having a thickness of 0.8 mm was cut into 100 × 250 mm, degreased and pickled, and then nickel or nickel-manganese alloy electroplating was performed under the following conditions using a medium electroplating apparatus capable of circulating the solution. The solution used here was a sulfuric acid bath such as nickel sulfate or manganese sulfate, and ammonium sulfate was used as the supporting salt. The amount of adhesion was determined by keeping the current constant and adding or subtracting the plating time according to the theoretical formula.

Metal ion concentration: Ni ^{2 +} 15 g / l, Mn ^{2 +} 3g / l

- sulfate ion concentration: SO ₄ ^{2 -} 10g / l

Temperature: 50 ^o C

   pH: 4.5

Current density: 20A / dm ²

-Weight: 0.5 ~ 1100mg / m ²

A Ni or Ni-X alloy plated layer was formed as a lower layer, and a coated phosphate solution having various conditions was coated on one surface of the GA steel plate with a bar coater No. 3, and dried at 70 ° C. to form a phosphate film to prepare a specimen.

Thereafter, the adhesion, coefficient of friction and chemical conversion treatment for the prepared composition were evaluated.

Adhesiveness was cut into three pieces of 100 x 25 mm per condition, degreased with alcohol acetate, and again immersed in R303-PX2 cleaning oil 25 mm, and left for one day. After 24 hours, hemp flange adhesive (PV5308, manufactured by Semedane-Henkel, Toyota Motor Co., Ltd.) was applied to the 25 x 25 mm section only, dried at 150 ° C for 20 minutes, and then shear sheared at 50 mm / min. The cohesive failure rate of the adhesive was determined by observing the fractured form of the tested and finished specimens.

The cohesive failure rate of the used PV5308 hemp flange adhesive must be 100%, which means that no interface peeling occurs between the adhesive and the steel sheet.

The friction coefficient was cut to 45x150mm and coated with automotive cleaning oil (P-DBH) .Then, 650kgf load was applied to a 3.5cm x 3.5cm die and drawn at a drawing speed of 1000mm / min. The coefficient of friction was measured by dividing by 650kgf load.

The coefficient of friction is measured in three for each specimen and the average value is shown in Table 1 below.

Mars treatment was carried out under the conditions used by H Motor Company in Korea.

The surface was first adjusted by immersing the specimen in PN-Z 2g / l solution for 150 seconds and then subjected to the main chemical treatment for 150 seconds in a BT699D 60g / l solution at 45 ° C.

The treated specimens were rinsed and dried, and the grain size was measured by observing the tissue with an electron microscope. If the grain size was 5 microns or less, the chemical conversion was excellent (○), and 5 to 10 microns were normal (△). , 10 micron or more was determined to be inferior (x) and shown in Table 1 below.

In addition, when the coating amount of the lower layer and the upper layer was more than the upper limit set forth in the present invention, it was determined that the processability, adhesiveness, and chemical conversion processability were not improved any more, so it was not economical.

In addition, even when the upper film composition exceeds the upper limit shown in the present invention, it is determined that the improvement of the quality characteristics is not economical.

Psalm No. Coating amount of nickel / nickel alloy plating layer (mg / m ² ) Phosphate Treatment Layer (Upper Layer) Friction coefficient Adhesive Cohesion Fracture Rate (%) Mars treatability Economics P amount (wt%) Zn amount (wt%) Mn amount (wt%) Coating amount (mg / m ² ) Conventional example One - - - - - 0.224 0 × Comparative example 2 One - - - - 0.210 0 ○ 3 1000 - - - - 0.205 0 ○ 4 0.5 40 50 10 150 0.159 100 × 5 1100 50 40 10 400 0.158 100 △ × 6 100 30 60 10 1000 0.195 100 ○ × 7 - 50 35 15 1500 0.154 100 × 8 - 40 50 10 2000 0.151 100 × 9 - 50 40 10 1000 0.155 100 × 10 One 50 40 10 5 0.189 50 ○ 11 50 50 40 10 5 0.189 50 ○ 12 600 70 20 10 1000 0.152 100 ○ 13 1000 50 40 10 2100 0.151 100 ○ × 14 100 50 20 30 1000 0.156 100 ○ × 15 10 - - - - 0.223 0 ○ × Inventive Example One One 40 40 20 10 0.156 100 ○ 2 One 50 45 5 500 0.154 100 ○ 3 One 60 30 10 2000 0.145 100 ○ 4 1000 40 50 10 10 0.158 100 ○ 5 1000 50 40 10 500 0.152 100 ○ 6 1000 60 30 20 2000 0.143 100 ○ 7 500 40 45 15 10 0.158 100 ○ 8 500 50 45 5 600 0.149 100 ○ 9 500 60 30 10 2000 0.145 100 ○ 10 10 40 40 20 10 0.157 100 ○ 11 10 50 30 20 1000 0.150 100 ○ 12 10 60 35 5 2000 0.148 100 ○ 13 One 50 45 5 10 0.156 100 ○ 14 One 50 40 10 2000 0.149 100 ○ 15 1000 50 30 20 10 0.155 100 ○ 16 1000 50 45 5 2000 0.148 100 ○

As shown in Table 1, in the case of the conventional example 1, the friction coefficient is very high as 0.224, and it can be predicted that the workability is inferior, and the adhesion and the chemical conversion treatment are not good.

On the other hand, when the nickel or nickel-based alloy plated layer is formed on the GA steel sheet as in Comparative Examples 2 and 3, the chemical conversion treatment is good, but the adhesiveness and workability are inferior. The adhesiveness was excellent, but the chemical conversion was inferior.

In addition, as in Comparative Examples 4 to 6 and 10 to 15, even when both the lower layer and the upper layer were formed, if the film deposition amount and the film composition were lower than those proposed in the present invention, the target quality characteristics could not be exhibited and, on the contrary, the deposition amount If the film composition is outside the upper limit, it is not economically expected to improve the quality.

On the contrary, as in Examples 1 to 16 of the present invention, the friction coefficient of the upper and lower layers and the coating composition (P, Zn, Mn) of the upper layer satisfying the values suggested in the present invention are 0.16 or less. It can be seen that the adhesiveness is good and exhibits 100% cohesive failure rate, and the chemical conversion treatment is excellent in grain size of 5 microns or less.

1 is an electron micrograph showing the crystal structure of the Ni-treated GA steel sheet and the Ni-treated GA steel sheet according to the Ni adhesion amount

Claims (13)

A nickel (Ni) or nickel alloy plating layer is formed on the zinc plating layer or the zinc-based alloy plating layer of the zinc or zinc alloy plating steel sheet having a zinc plating layer or a zinc-based alloy plating layer, and a phosphate as an upper coating on the lower layer coating. A film is formed, The adhesion amount of the lower layer is 1 ~ 1000mg / m ² , the adhesion amount of the upper layer is 10 ~ 2000mg / m ² , The phosphate film is formed by applying a coating composition comprising 1 to 30% by weight of hypophosphorous acid, 0.1 to 10% by weight of manganese, zinc oxide and the balance on the lower layer film, and drying it. The zinc oxide in the coating composition is included in an amount such that the amount of NaOH consumed for neutralization titration is 10.0 ml or less when neutralizing titration of 50 ml of the coating composition with 0.1 N NaOH, and the content of the free acid in the coating composition. When 50 ml of silver coating composition is neutralized with 0.1 N NaOH, the amount of NaOH consumed in the neutralization titration is controlled to be 10.0 ml or less. Interlocking Alloy Plated Steel Sheet The zinc or zinc-based alloy plated steel sheet having excellent workability, adhesion and chemical conversion treatment, characterized in that the Ni content in the nickel alloy plating layer is 90% by weight or more. The zinc or zinc-based alloy plated steel sheet excellent in workability, adhesiveness and chemical conversion treatment according to claim 1 or 2, wherein the lower layer is formed by electroplating. The zinc or zinc-based alloy plated steel sheet according to claim 1 or 2, wherein 0.01 to 5% by weight of a polyvinyl compound is additionally added to the coating composition. According to claim 3, Zinc or zinc-based alloy plated steel sheet excellent in workability, adhesiveness and chemical conversion treatment, characterized in that the addition of 0.01 to 5% by weight of the polyvinyl compound to the coating composition A nickel (Ni) or a nickel alloy plating layer is formed on the zinc plating layer or the zinc-based alloy plating layer of the zinc or zinc-based alloy plated steel sheet having a zinc plating layer or a zinc-based alloy plating layer, and a 40-layer coating is formed on the lower coating. A phosphate film containing ˜60% by weight of phosphorus (P), 30-50% by weight of zinc (Zn) and 1-20% by weight of manganese (Mn) is formed, and the adhesion amount of the lower layer is 1-1000 mg / m ² and the coating amount of the upper layer is 10 ~ 2000mg / m ² zinc, zinc-based alloy plated steel sheet excellent in workability, adhesiveness and chemical conversion treatment The zinc or zinc-based alloy plated steel sheet having excellent workability, adhesion and chemical conversion treatment, characterized in that the Ni content in the nickel alloy plating layer is 90% by weight or more. The zinc or zinc-based alloy plated steel sheet according to claim 6 or 7, wherein the lower layer film is formed by an electroplating method. The zinc or zinc-based alloy plated steel sheet according to claim 6 or 7, further comprising 0.01 to 5% by weight of a polyvinyl compound in the upper layer. The zinc or zinc-based alloy plated steel sheet having excellent workability, adhesiveness and chemical conversion treatment, characterized in that the upper film further comprises 0.01 to 5% by weight of a polyvinyl compound. Forming an underlayer film comprising a nickel (Ni) or nickel alloy plating layer having an adhesion amount of 1 to 1000 mg / m ² on the zinc plating layer or zinc alloy plating layer of the zinc or zinc alloy plating steel sheet having a zinc plating layer or a zinc alloy plating layer; ; And 1-30% by weight of hypophosphorous acid, 0.1-10% by weight of manganese, zinc oxide and the remainder of the coating composition, the zinc oxide is neutralized titration when neutralizing titration 50ml of the coating composition with 0.1N NaOH The amount of NaOH consumed in 10.0ml or less is included, and the amount of free acid in the coating composition is the amount of NaOH consumed in neutralization titration when neutralizing titrating 50mL of the coating composition with 0.1N NaOH. Processability, adhesiveness and chemical conversion treatment comprising the step of preparing a coating composition controlled in an amount of 10.0ml or less, coating and drying the coating on the lower layer to 10 ~ 2000mg / ㎡ to form an upper layer coating Manufacturing method of zinc or zinc-based alloy plated steel sheet with excellent properties The method of manufacturing a zinc or zinc-based alloy plated steel sheet excellent in workability, adhesion and chemical conversion treatment, characterized in that the lower layer is formed by electroplating. The zinc or zinc-based alloy plated steel sheet of claim 11 or 12, wherein 0.01 to 5% by weight of a polyvinyl compound is further added to the coating composition. Manufacturing method

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