JPH07138766A - Formation of zinc phosphate composite film layer excellent in high speed press formability on zinc-containing metal plated steel sheet - Google Patents

Abstract

PURPOSE:To form a zinc phosphate composite film layer excellent in high speed press formability on a Zn-contg. metal plated steel sheet by subjecting the surface of a Zn-contg. metal plated steel sheet to activating treatment and thereafter treating it by a soln. of chemical conversion treatment having a specified compsn. CONSTITUTION:A galvanized steel sheet or a galvannealed steel sheet is previously treated by an Ni or Co ion-contg. soln. or a Ti colloidal aq. soln. to activate its surface. Next, it is treated by a soln. of chemical conversion treatment contg. 10 to 30g/l of phosphoric acid ions, 1.0 to 15g/l of nitric acid ions, 0.1 to 8.0g/l of Zn ions, 0.1 to 8.0g/l of at least one kind of metallic ions among Fe, Ni, Mn, Co, Ca and Mg and at least one kind of fluoride ions and complex fluoride ions by 0.1 to 3.0g/l expressed in terms of fluorine ions or moreover, in which nitrous acid ions contain a reaction accelerator such as inorganic peroxide and hydrogen peroxide, the weight ratio of Zn ions to the other metallic ions is regulated to (0:1: 1) to (10: 1) and the acid ratio of the total acidity to free acidity is regulated to (8:1) to (30:1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical conversion treatment method for forming a zinc phosphide composite coating suitable for imparting excellent high-speed press formability required for manufacturing automobile bodies to zinc-containing metal plated steel sheets. It is about.

[0002]

2. Description of the Related Art Conventionally, when press-forming a steel sheet, a lubricating oil containing a press oil or a wax and having a relatively high viscosity is widely and generally used. On the other hand, the amount of zinc-containing metal-plated steel sheets with improved rustproofing is also increasing in the steel sheets used after being formed by pressing or the like.

However, in the zinc-containing metal-plated steel sheet, zinc in the plating layer is relatively soft and has a low melting point.
Since the temperature of the mold is high during press molding, zinc tends to adhere. As a method for improving the press formability of such a zinc-containing metal-plated steel sheet, for example, JP-A-62-192597 discloses a zinc-containing metal-plated steel sheet surface which is further hard-plated with an iron-zinc alloy and pressed. A method for preventing galling between the steel plate surface and the mold at that time is disclosed.

As a base treatment for plastic working such as wire drawing, pipe drawing, and forging of steel, a zinc phosphate-based coating having a low unit price and stable performance is used, but the treatment time is long. Since it takes 5 to 10 minutes, when it is used for in-line or the like, productivity is deteriorated and it is not industrial.

Further, in recent years, in the automobile body manufacturing process, in order to improve the productivity and reduce the manufacturing cost, press molding is performed at a higher speed than ever before. Further, by molding a complicated shape by an integral press, the assembly process can be simplified and the manufacturing cost can be reduced, and it is difficult to deal with the conventional techniques such as press oil and lubricating oil.

On the other hand, in order to improve the anticorrosive power of automobile bodies, the use ratio of zinc-containing metal-plated steel sheets to automobile bodies tends to increase more and more, and improvement of high-speed press formability is important. Therefore, as an improvement method thereof, Japanese Patent Application Laid-Open No. 62-192597 discloses a method of forming an alloy plating of zinc and iron on the surface of a zinc-containing metal-plated steel sheet by an electroplating method. However, there are drawbacks such as increased equipment cost and electric cost during manufacturing.

In Japanese Patent Laid-Open No. 63-162886, the surface of a zinc-based plated steel sheet is coated with a composite coating of an inorganic coating and an organic coating provided with lubricity, and there is an opportunity for direct contact between the plated surface and the mold. It is disclosed that the press formability of a zinc-based plated steel sheet is improved by reducing or,
JP-A-1-201448 discloses a method of coating with an organic composite silicate coating to improve press formability.

However, in both of the above methods, the film thickness of the organic composite film varies depending on the degree of press molding, so the film thickness during electrodeposition coating tends to vary, and the film clarity required for automobile bodies is improved. Is impaired, so it is difficult to put it into practical use.
Therefore, at present, there is no technology capable of providing a zinc-containing metal-plated steel sheet excellent in coating film adhesion, coating film clarity, corrosion resistance after coating, and high-speed press formability and at low cost.

[0009]

DISCLOSURE OF THE INVENTION The present invention relates to a zinc-containing metal-plated steel sheet used particularly for automobile bodies, and has a coating film having required coating adhesion, coating clarity, and post-coating corrosion resistance. It is an object of the present invention to provide a method for forming a zinc phosphate composite film which is excellent in formability and can be used especially for high speed press forming without deteriorating the quality.

[0010]

Means for Solving the Problems As a result of intensive studies to solve these problems, the present inventors have found that a clean zinc-plated steel sheet contains phosphate ions and nitrate ions,
Zinc ion, one or more selected from iron ion, nickel ion, manganese ion, cobalt ion, calcium ion and magnesium ion, and at least one selected from fluoride ion and complex fluoride ion. 1 to 20 at a temperature of 30 to 70 ° C. using a chemical conversion treatment liquid containing zinc ions and other total metal ions in a weight ratio and having a specific acid ratio (free acidity / total acidity). The zinc-containing metal-plated steel sheet obtained by contacting for seconds has high speed press formability without impairing the coating quality such as coating adhesion, coating clarity, and corrosion resistance after coating required for automobile bodies. Was newly found to have an excellent zinc phosphate composite coating, and the present invention has been completed.

The method of forming the zinc phosphate composite coating layer excellent in high-speed press formability on the zinc-containing metal-plated steel sheet according to the present invention comprises the following components (1) to (5) on the surface of the zinc-containing metal-plated steel sheet. ): (1) Phosphate ion 10 to 30 g / liter (2) Nitrate ion 1.0 to 15 g / liter (3) Zinc ion 0.1 to 8.0 g / liter (4) Iron ion, nickel ion, manganese ion , At least one metal ion selected from cobalt ion, calcium ion, and magnesium ion 0.1 to 8.0 g / liter (5) Fluoride ion and complex fluoride ion At least one selected from 0.1 to 3.0 g / liter is contained, and the weight ratio of zinc ions to other total metal ions is 0.1: 1 to 10: 1. There, and acid ratio to free acidity of total acidity is 8: 1 to 30: 1 and is chemical conversion treatment liquid, is characterized in that the contacting 20 seconds at a temperature of 30 to 70 ° C..

In the method of the present invention, the chemical conversion treatment liquid is
Further, (6) 0.05 to 0.8 g / liter of nitrite ion, or (7) 0.01 to 0.7 g / liter of at least one selected from inorganic peroxide and hydrogen peroxide. It is preferably contained as an accelerator.

In the method of the present invention, the surface of the zinc-containing metal-plated steel sheet is treated with a treatment liquid containing at least one selected from (a) nickel ions and cobalt ions before the chemical conversion treatment, and the surface is treated. Above, at least one or more selected from nickel and cobalt,
It is preferable to carry out an activation treatment for depositing with a metal deposition amount of 0.2 to 50 mg / m ² or an activation treatment for treating with a (b) titanium colloid aqueous solution.

[0014]

The zinc-containing metal-plated steel sheet used in the method of the present invention is zinc, or zinc and other elements such as nickel,
It is a steel plate plated with an alloy of one or more selected from iron, aluminum, manganese, chromium, lead, antimony, and the like. The plating method is not particularly limited, and hot dip galvanizing method, hot dip galvanizing method, electrogalvanizing method, and electrogalvanizing alloy (Zn-Ni, Zn
-Fe, Zn-Mn or Zn-Cr alloy) plating method, hot-dip Zn-Al plating method, vapor deposition plating method and the like.

In the chemical conversion treatment liquid used in the method of the present invention, the source of phosphate ions is not particularly limited, but orthophosphoric acid is usually used and the content of phosphate ions is 1
It is 0 to 30 g / liter. If the content of phosphate ions is less than 10 g / liter, the efficient short-time treatment which is the object of the present invention becomes difficult, and if it exceeds 30 g / liter, it is preferable for shortening the treatment time, but wasteful chemicals are consumed. Because it does, it becomes economically disadvantageous. The source of nitrate ions is not particularly limited, but nitric acid is usually used.
The content of nitrate ions is 1.0 to 15 g / liter.
When the content of nitrate ion is less than 1.0 g / liter, short-time treatment becomes difficult, and when it exceeds 15 g / liter, the effect of shortening the treatment time reaches saturation and the consumption of chemicals also increases. Will be at a disadvantage.

The metal ion supply source is not particularly limited, but a phosphate or nitrate is usually used. The metal ion must have a valence of 2 or more, contains 0.1 to 8.0 g / liter of zinc ion as an essential component, and further contains iron ion, nickel ion, manganese ion,
At least one metal ion selected from cobalt ion, calcium ion, and magnesium ion is used as a metal ion.
1 to 8 g / liter is contained. The weight ratio of zinc to other divalent or higher valent metal ions (zinc / total other metal ions) is controlled to 0.1: 1 to 10: 1. If the content of the other metal ions is less than 0.1 g / liter, it becomes difficult to efficiently form a film, and thus short-time treatment becomes impossible. If it exceeds 8 g / l, efficient film formation cannot be achieved. It is possible to reduce the processing time, but it is economically disadvantageous because wasteful chemicals are consumed.

If the weight ratio of zinc to all other divalent or higher valent metal ions is less than 0.1: 1, the content of divalent metal in the coating reaches saturation, and the improvement in high-speed press formability is saturated. In addition, the manufacturing cost increases. Also, it is 10: 1
When it exceeds, the content of the divalent metal in the coating decreases, so that the heat resistance of the coating becomes poor and the zinc phosphate composite coating easily breaks.

The sources of the fluoride ions and complex fluoride ions contained in the chemical conversion treatment solution used in the method of the present invention are not particularly limited, but hydrofluoric acid, silicofluoric acid, borofluoric acid, titanium hydrofluoric acid, and Zircon hydrofluoric acid or the like can be used, and at least one of these is
It is contained in a content of 0.1 to 3.0 g / liter in terms of fluorine ions. If the content of the fluorine-containing ions in the chemical conversion treatment liquid is less than 0.1 g / liter, the etching power for the zinc-containing metal-plated steel sheet will be insufficient, and it will take a long time to form the zinc phosphate composite chemical conversion film, which will increase the manufacturing cost. It is economically disadvantageous, and it is 3.0g /
If it is contained in a large amount exceeding liter, etching becomes excessive, which is not preferable.

The acid ratio (total acidity / free acidity) of the chemical conversion treatment liquid containing the above components is preferably 8: 1 to 30: 1. In the present invention, the total acidity means the chemical conversion treatment solution 10
ml was sampled using a whole pipette and titrated with a 0.1 N sodium hydroxide aqueous solution until the pH reached 8.3, and the volume of the sodium hydroxide aqueous solution required for this was expressed. The free acidity means that 10 ml of the chemical conversion treatment liquid is sampled using a whole pipette and titrated with a 0.1 N sodium hydroxide aqueous solution until the pH becomes 3.8, and the volume of the sodium hydroxide aqueous solution required for this is measured. Is represented by. If the acid ratio is less than 8: 1, the zinc-containing metal-plated steel sheet is etched more than necessary, which hinders efficient film formation. On the other hand, when the acid ratio exceeds 30: 1, the etching power becomes insufficient, and it takes a long time to form the zinc phosphate composite film, which causes an increase in manufacturing cost and is economically disadvantageous. The acid ratio can be adjusted by adding an acid such as phosphoric acid or nitric acid or an alkali such as sodium carbonate or sodium hydroxide to the chemical conversion treatment liquid.

Further, as a reaction accelerator for forming the zinc phosphate composite film in the present invention, nitrite ion is added in an amount of 0.1.
05-0.8 g / l or 0.01-0.7 at least one selected from inorganic peroxides and hydrogen peroxide.
It is preferable to contain g / liter. There is no particular limitation on these sources. If the amount of the accelerator added is less than the specified lower limit value, the zinc phosphate composite chemical conversion film formation promoting effect becomes insufficient, and the effect reaches saturation even if it is contained in excess of the specified upper limit value, Increased drug consumption is economically disadvantageous.

The zinc phosphate compound formed by the method of the present invention
There is no particular limitation on the composition of the composite film, but zinc phosphate composite
Phosphorus content in the coating film is 40-420mg / m²,zinc
Content of 130-1300mg / m²Like to be,
In addition to this, further selected from nickel and manganese
0.2 to 200 mg / m in terms of metal of at least one kind ²
High-speed press working by forming zinc phosphate composite film containing
When used for the purpose, mineral oil, natural fats and oils,
One or more selected from synthetic ester and wax
The upper oil layer is 0.2-2 g / m²Can be formed with a coating amount of
And are preferred.

Phosphorus and zinc in the zinc phosphate composite conversion coating formed by the method of the present invention are the main constituents of this coating, and the phosphorus content is 40 to 420 mg / minute as described above.
m ² , and the content of zinc is 130 to 1300 mg / m
^{Is 2} . If the content of each is less than the above lower limit value, the holding power of the oil layer applied thereon is insufficient, so that the high speed pressability is deteriorated. Further, when the content of each exceeds the above upper limit, during the press forming, a broken zinc phosphate composite chemical conversion film is deposited in the press die and is pushed into the surface of the galvanized steel sheet as a foreign matter, resulting in press scratches. It is not preferable because it is easy to do.

In order to impart excellent high-speed press formability to the zinc phosphate composite conversion coating, at least one selected from nickel and manganese is contained in the coating in an amount of 0.2 to 200 mg / m in terms of metal. ² is preferably contained.
When the content of the above metal is less than 0.2 mg / m ² , the high speed press molding performance is insufficient, and it is 200 mg / m 2.
^When it exceeds ² , the high-speed press formability reaches saturation, which is economically disadvantageous.

Further, as described above, in the method of the present invention, a zinc phosphate composite conversion coating is formed on the surface of a zinc-containing metal-plated steel sheet, and then an oil layer is formed thereon in an amount of 0.2 to ² g / m ^2. It is preferable to form it with the coating amount of. As the oil layer to be applied, it is preferable to use one or more oils selected from mineral oils, natural oils and fats, synthetic ester oils and waxes.

As a short-time treatment method which is one of the objects of the present invention, a clean zinc-based plated steel sheet surface is
After performing the following (a) or (b) activation treatment in advance,
It is preferable to keep the above chemical conversion treatment liquid at a temperature of 30 to 70 ° C. to treat the surface of the zinc-containing metal-plated steel sheet that has been activated. If the temperature of the chemical conversion treatment liquid is lower than 30 ° C., the film formation rate becomes slow, and short-time treatment becomes difficult. On the other hand, even if it is heated to a temperature higher than 70 ° C., the treatment effect is saturated, which is rather economically disadvantageous.

In the method of the present invention, the chemical conversion treatment liquid is brought into contact with the surface of the zinc-containing metal-plated steel sheet for 1 to 20 seconds. If the contact time is less than 1 second, sufficient film formation is not performed, and if it exceeds 20 seconds, the film formation reaches saturation, which is wasteful. The contact method is not limited, but a spray method or a dipping method is usually used.

The activation treatment in the method of the present invention includes:
(B) Treated with a treatment liquid containing nickel ions and / or cobalt ions to obtain nickel or cobalt or both of them in an amount of 0.2 to 50 mg / m in terms of metal.
It is preferable to perform the treatment of attaching ² or the treatment of contacting with the (b) titanium colloid aqueous solution.

In the case of the above-mentioned (a) activation treatment, it is treated with a treatment liquid containing nickel ions and cobalt ions or both, and nickel or cobalt or both are 0.2 to 50 mg / m ^{2 in} terms of metal. Is to be attached. The amount of activator attached is 0.2 mg / metal equivalent
If it is less than m ² , the activation of the steel sheet surface is insufficient, and short-time treatment becomes difficult. Further, even if it exceeds 50 mg / m ² , the effect obtained is saturated and becomes economically disadvantageous.

There are no particular restrictions on the source of nickel ions and cobalt ions that can be used in the activation treatment liquid of (a) above, but water-soluble nickel salts such as nickel sulfate, nickel nitrate, nickel chloride, nickel fluorosilicate, etc. It is preferable to use water-soluble cobalt salts such as cobalt sulfate, cobalt nitrate, cobalt chloride and cobalt silicofluoride alone or in any combination.

The source of titanium ions in the titanium colloid used for the activation treatment (b) is not particularly limited, but titanium sulfate, titanyl nitrate, titanium oxide, titanium phosphate, etc. may be used alone or respectively. It is preferable to use two or more of them in any combination.

On the surface of a clean zinc-based plated steel sheet, (a)
Alternatively, after the activation treatment by the method (b), the zinc phosphate composite chemical conversion coating film is treated with the zinc phosphate composite chemical conversion coating treatment liquid described above, whereby the zinc phosphate composite chemical conversion coating is efficiently treated within a short time of 1 to 20 seconds. It is possible to form it high.

Zinc phosphate chemical conversion treatment is a technique with a long history in the surface treatment of steel materials, and it is still used as a pretreatment for coating, as a pretreatment for lubrication in cold working such as wire drawing and pipe drawing. Widely used. Regarding the effect of the zinc phosphate conversion coating as the coating base, it is considered that the adhesion is improved by the physical shape of the coating and by the anchoring effect on the coating. Further, the effect of the base treatment before the lubrication treatment in the cold working is that the holding power of the solid soap calcium soap is increased,
It is considered that the zinc phosphate conversion coating itself also has a function as a solid lubricant.

The action and effect on the zinc-containing metal-plated steel sheet according to the method of the present invention is basically considered to be the same as the action in cold working. Even in the case of a simple zinc phosphide chemical conversion film that actually consists of phosphoric acid and zinc, it can withstand practical use sufficiently if the punch speed, which is the main factor that determines the normal press-molding speed, is a low speed of a few m / min or less. It is a thing.

Therefore, in order to improve the productivity and reduce the manufacturing cost, the press forming speed is increased and the punch speed is 10 m /
When press forming at a high speed exceeding the above is applied to a zinc-containing metal-plated steel sheet coated with a simple zinc phosphide conversion coating, the coating cannot follow high-speed press forming, resulting in destruction of the chemical conversion coating, plating peeling, etc. Scratch on the surface of the material,
Occurrence of indentation damage and further material breakage will occur.

Generally, a zinc phosphate conversion coating is a Zn ₃ (PO
₄₎ those comprising a crystal of ₂ · 4H ₂ O (hopeite), the peak temperature of the endothermic reaction by dehydration of two crystal water is 120 ° C.
It is well known that it is in the vicinity. On the other hand, when the zinc phosphate conversion treatment is applied to the steel sheet surface, Zn ₂ F
e (PO ₄₎ crystals have been known to produce a ₂ · 4H ₂ O (phosphate Hoo pyrophyllite), the peak temperature of the endothermic reaction by dehydration of two crystal water in the crystal, the dehydration of hopeite The temperature shifts to about 40 ° C higher than the temperature, 160
It is known to be around ℃. Other than iron, calcium, nickel, manganese, and the like are known as metals that shift the dehydration temperature to a high temperature side from the peak temperature of the endothermic reaction due to dehydration from a simple hopeite crystal.
Further, the dehydration of this crystal water causes the crystal to shrink in volume, and the physical strength of the crystal itself decreases. That is, it is considered that the heat resistance of the coating is improved by shifting the dehydration temperature to the high temperature side.

As a function and effect of the zinc phosphate composite chemical conversion coating formed on the zinc-containing metal plated steel sheet by the method of the present invention, the heat resistance of the coating as described above is improved. That is,
In press molding at a relatively low speed, the heat generated during pressing is small, and therefore the surface temperature of the material is relatively low. Therefore, even a normal zinc phosphate coating can be sufficiently molded. However, in a high-speed press, a large amount of heat is generated, which causes the material surface temperature to reach a considerably high temperature. Therefore, a zinc phosphate composite chemical conversion coating film containing nickel, manganese, etc. having excellent heat resistance is formed by the method of the present invention. It is speculated that this will be effective.

[0037]

EXAMPLES The present invention will be described in detail with reference to the following examples, but the scope of the present invention is not particularly limited by these examples.

Examples 1-42 and Comparative Examples 1-30 1. Sample material Commercially available double-sided alloyed hot-dip galvanized steel sheet with a thickness of 0.8 mm (GA material: basis weight 60 g / m ² ), double-sided electrogalvanized steel sheet (EG material: basis weight 20 g / m ² ), both sides Electric Z
n-Ni alloy plated steel sheet (Zn-Ni material: basis weight 20 g
/ M ² ) was used as a test plate.

2. Method for forming composite chemical conversion film A composite chemical conversion film was formed on the surface of the test material by the following treatment steps. Degreasing → Washing → Activation → Composite film treatment → Washing → Deionized water washing

2.1. Degreasing treatment Sodium phosphate-based alkaline degreasing agent (trademark: Fine Cleaner L4480, Nippon Parkerizing Co., Ltd.)
Degreasing treatment was performed. <Degreasing conditions> Chemical concentration: 18 g / liter, processing temperature:
45 ° C, treatment time: 120 seconds, spray treatment

2.2. Washing with water after degreasing The alkali content remaining on the surface of the steel sheet was removed by washing under degreasing treatment under the following conditions. <Washing conditions> Water used: tap water, treatment temperature: normal temperature, treatment time: 20 seconds, spray treatment

2.3. Activation Treatment (1) Activation treatment was performed using the treatment liquid (a) having the composition shown in Table 1. Activation treatment agent: Trademark: PREPAREN Z, manufactured by Nippon Parkerizing Co., Ltd.

[0043]

[Table 1]

<Processing conditions> Processing temperature: normal temperature, processing time:
Spray treatment for 2 seconds, or (2) Nickel sulfate aqueous solution (a) having the composition shown in Table 2,
Alternatively, an aqueous solution of cobalt sulfate (c) was used to deposit nickel and cobalt on the surface, followed by washing with water. However, the washing conditions were the same as in (2.2.).

[0045]

[Table 2]

<Treatment conditions> Treatment temperature: 60 ° C., treatment time: 1 to 10 seconds, spray treatment

2.4. Composite chemical conversion coating treatment Using the chemical conversion treatment liquids A to T having the compositions shown in Table 3, a composite chemical conversion coating was deposited on the surface of the test material.

[0048]

[Table 3]

<Composite conversion coating treatment conditions> Treatment temperature: 30 ° C, 45 ° C, 50 ° C, 75 ° C Treatment time: 0.5 to 20 seconds, dipping treatment

2.5. Washing with water after chemical conversion treatment The chemical conversion treatment liquid remaining on the surface of the steel sheet by the composite chemical conversion coating treatment was removed by washing under the following conditions. <Washing conditions> Water used: tap water, treatment temperature: normal temperature, treatment time: 20 seconds, spray treatment

2.6. Deionized water washing After the water washing treatment, washing with deionized water was carried out in order to remove contaminant ions contained in the water remaining on the surface of the steel sheet. <Deionized water washing conditions> Water used: Deionized ionized water, Treatment temperature: Room temperature, Treatment time: 20 seconds, Spray treatment

3. Composition, evaluation of composite chemical conversion film The composition of the film of the obtained composite chemical conversion film is shown in Table 4, Table 5 and Table 6.

4. Evaluation Test Method The evaluation test results of the composite chemical conversion coating are shown in Tables 4, 5, and 6. However, the evaluation test was performed as follows. 4.1. Film characteristics 4.1.1. Coating weight (amount of zinc adhered mg / m ² and amount of nickel adhered mg / m ² (* ₁ )) The weight of the zinc phosphate composite chemical conversion coating was measured by the following method. (1) The weight of the test piece (W1: m
g) was measured and immersed in an ammonium dichromate solution (* ₂ ) having the following composition for 15 minutes at room temperature. [Note] * ₁ ... The amount of nickel deposited by the atomic absorption method was measured only for the Zn-Ni material. * ₂ ... Ammonium dichromate solution composition: Ammonium dichromate: 20 g / l 25% ammonia water: 490 g / l Deionized water: 490 g / l

(2) Next, the test piece was washed with water to remove the ammonium dichromate solution remaining on the test piece and dried. (3) The weight (W2: mg) of the test piece was measured again with a precision balance, and the coating weight per unit area was calculated from the weight difference (W1-W2). (4) Further, using the ammonium dichromate solution used for measuring the coating weight, the amount of zinc and the amount of nickel were analyzed by an atomic absorption method, and the amount of zinc deposited and the amount of nickel deposited per unit area were calculated.

4.1.2. Adhesion amount of phosphorus, nickel (* ₃ ), manganese, iron, cobalt, calcium, and magnesium (mg / m ² ) Phosphorus, nickel in the composite chemical conversion film by the fluorescent X-ray method
The amount of manganese, iron, cobalt, calcium and magnesium adhered was measured. [Note] * ₃ ... The amount of nickel deposited on the Zn—Ni material was not measured by the fluorescent X-ray method.

4.2. Machining performance test 4.2.1. High-speed deep drawing test A 115 mmφ test piece was coated with a rust preventive oil containing mineral oil as a main component at a coating amount of 1.5 g / m ² , and a punch diameter of 5
A high-speed deep drawing test was performed under the conditions of 0 mmφ, deep drawing speed: 30 m / min, and drawing ratio: 2.3. Under these conditions, the wrinkle pressing load (t) was changed stepwise, and the limit wrinkle pressing load (t) when the drawing was just finished was measured.

4.2.2. Flat plate pull-out test A 30 mm x 300 mm test piece was coated with a rust preventive oil containing mineral oil as a main component at a coating amount of 1.5 g / m ² , and a crimping load = 1
The pull-out load (kg) at the time of pulling out at 00 kgf and the pulling-out speed = 260 mm / min was measured.

4.2.3. The rust-preventive oil consisting mainly of mineral oil specimen Bowden testing 70 mm × 150 mm, was coated at a coverage of 1.5 g / m ^2, the pressure load: 1 kg
f, crimping element: SUJ-2 (steel ball of 10 mmφ), sliding speed: The number of times of sliding until the occurrence of seizure at 8 mm / sec was measured.

[0059]

[Table 4]

[0060]

[Table 5]

[0061]

[Table 6]

As is clear from the results of Tables 4, 5 and 6, Examples 1 to 42 of the present invention show good results in the high speed deep drawing test, the flat plate drawing test and the Bowden test. None of Examples 1 to 30 had good test results, and the results of these high-speed deep drawing tests were considerably inferior to those of Examples.

[0063]

The zinc phosphate composite coating formed on the galvanized steel sheet by the production method of the present invention is the same as the conventional press oil,
It is possible to apply it to parts that cannot be handled by the technology using only lubricating oil.
It is possible to obtain high quality products at low cost compared to the integral molding of complicated shapes and to improve productivity. Further, the zinc phosphate composite coating can be subjected to chemical conversion treatment after pressing, has high versatility and can be applied not only in the automobile field but also in a wide range of fields such as home appliances and building materials.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Aoyama 1-15-1 Nihonbashi, Chuo-ku, Tokyo Within Japan Parkerizing Co., Ltd. (72) Inventor Shigeru Chikada 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (72) Inventor Shuntaro Sudo 1 Toyota-cho, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Hiroshi Kawaguchi 1-cho, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Shin Fukada 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd.

Claims (3)

[Claims] 1. The following components (1) to (5) on the surface of a zinc-containing metal plated steel sheet: (1) Phosphate ion 10 to 30 g / liter (2) Nitrate ion 1.0 to 15 g / liter (3) Zinc ion 0.1-8.0 g / liter (4) At least one metal ion selected from iron ion, nickel ion, manganese ion, cobalt ion, calcium ion, and magnesium ion 0.1-8.0 g / Liter (5) Fluoride ion and complex fluoride a At least one kind selected from ON in terms of the amount of fluorine ion 0.1 to 3.0 g / liter is contained, and all other metal ions of zinc ion To the weight ratio of 0.
A chemical conversion treatment solution having a ratio of 1: 1 to 10: 1 and an acid ratio of total acidity to free acidity of 8: 1 to 30: 1 is contacted at a temperature of 30 to 70 ° C. for 1 to 20 seconds. A method for forming a zinc phosphate composite coating layer excellent in high-speed press formability on a zinc-containing metal-plated steel sheet. 2. The chemical conversion treatment liquid further comprises (6) nitrite ion of 0.05 to 0.8 g / liter, or (7) at least one selected from inorganic peroxide and hydrogen peroxide. The method according to claim 1, which contains 0.01 to 0.7 g / liter of seed as an accelerator. 3. The surface of the zinc-containing metal-plated steel sheet is treated with a treatment liquid containing at least one selected from (a) nickel ions and cobalt ions before the chemical conversion treatment, and nickel is applied onto the surface. And at least 1 selected from cobalt
The method according to claim 1 or 2, wherein an activation treatment of depositing at least one species with a metal deposition amount of 0.2 to 50 mg / m ² or an activation treatment of treating with (b) titanium colloid aqueous solution is performed. .