JPH0551761A - Surface treated steel sheet having excellent deep drawability - Google Patents

Abstract

PURPOSE:To provide the surface treated steel sheet which has an excellent lubricating characteristic to allow the omission of a pressing oil and has excellent corrosion resistance, adhesion of a finish coating material and weldability. CONSTITUTION:This surface treated steel sheet having excellent drawability is constituted by applying a chlorine-based lubricant to the underside of a chromate film or incorporating this lubricant into the chromate film of the org. film plated steel sheet formed by coating the surface of the galvanized steel sheet with the chromate film and a resin film into which silica and if necessary, the lubricant are incorporated on the above-mentioned chromate film. The galvanized steel sheet coated with the org. film having the excellent corrosion resistance, adhesion of the coating material, weldability and particularly press lubricity is provided in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-performance surface-treated steel sheet having excellent lubricity.

[0002]

2. Description of the Related Art Instead of a post-painted steel sheet which has been conventionally coated after processing, a surface-treated steel sheet coated with a thin organic film is used. This steel sheet has a zinc-based plating film as an underlayer, and is coated with an organic film, and is weldable, and has excellent characteristics in adhesion workability and corrosion resistance.

The disclosed technique is Japanese Patent Laid-Open No. 60-50.
181 and JP-A-63-162886. The former is a zinc-based plated steel sheet coated with a resin coating in which a chromate film and silica are dispersed in a dry film thickness of 0.01 to 4.0 μm. Also,
The latter is obtained by coating a zinc-based plated steel sheet with a chromate film and a resin coating in which silica and Teflon lubricant are dispersed in a dry film thickness of 0.01 to 4.0 μm to impart lubricity. These surface-treated steel sheets provide corrosion resistance, weldability, adhesion workability, and lubricity due to the combined effect of plating, chromate, and organic silicate coating, and are still under development for the purpose of quality improvement.

[0004]

The prior art is widely applied for expanding the range of use, such as bending and shallow drawing products. However, in order to thoroughly reduce costs in recent years, save labor, and solve environmental problems,
There is an increasing demand for the development of pre-coated lubricated steel sheets that can be used in the high-speed and deep-drawing field and that can omit press oil. High-viscosity lubricating oil has been used in high-speed deep-drawing, but conventional lubricating steel plates do not have sufficient quality equivalent to lubricating oil. Especially in high-speed machining, the viscoelasticity of the lubricating coating changes significantly due to the frictional heat between the die and the steel sheet. For resin coatings with a low softening point (glass transition point; Tg point), the resin coating has a high surface pressure and ironing due to continuous pressing. , "Gnailing" occurs. In particular, the water-based resin coating material has a low Tg point and is apt to cause galling, which is difficult to solve by the conventional technology. However, the water-based resin coating does not require solvent measures (exhaust gas, explosion), and is advantageous in terms of manufacturing because of its characteristics of low temperature and short time baking. Therefore, there is a demand for the development of a lubricating steel sheet using a lubricating resin that can omit press oil, particularly a water-based lubricating resin. It is an object of the present invention to provide a lubricated steel sheet that solves this problem.

[0005]

The subject matter of the present invention is as follows. (1) 10-100 mg in terms of Cr on the surface of plated steel sheet
/ M ² chromate film and silica resin coating containing 0.5 to 3.0 g / m ² as a dry adhesion amount of a resin film containing 5 to 50 parts by weight of solids based on 100 parts by weight of resin. In the plated steel sheet, one or more of chlorinated fatty acid, chlorinated fatty acid ester, and chlorinated paraffin compound is coated as a Cl adhesion amount in the lower layer of the chromate film of 1 to 30 mg / m ² or contained in the chromate film. Surface-treated steel sheet with excellent deep drawability, characterized by.

(2) 10 on the surface of the plated steel sheet in terms of Cr
A resin film containing a chromate film of ˜100 mg / m ² and silica in an amount of 5 to 50 parts by weight as a solid content with respect to 100 parts by weight of resin and a lubricant of 5 to 25 parts by weight as a dry adhesion amount of 0. In a resin-coated steel sheet coated with 5 to 3.0 g / m ² , at least one of chlorinated fatty acid, chlorinated fatty acid ester, and chlorinated paraffin compound is Cl
Surface-treated steel sheet with excellent deep drawability, characterized in that is contained in either or in the chromate film coated on the lower layer of 1 to 30 mg / m ² chromate coating as coating weight.

[0007]

The present invention has basically succeeded in developing a press-oil-free lubricating steel sheet in which a boundary lubrication film between the die and the steel sheet is formed on the plated surface and coated with chromate and resin paint. The main lubrication in press is the so-called fluid such as liquid and wax, which has a low friction coefficient or the organic solid lubrication, but in the high-speed deep-drawing press processing required here, the surface pressure is high and the processing speed is high. Because it is fast, normal lubricating oil and lubricating film are easily destroyed and removed. Therefore, adhesion is likely to occur due to contact between the mold and the steel plate, and galling occurs. In order to solve this problem, a lubricating oil is used in which the viscosity of the lubricating oil is increased and various additives are further added.

The lubricating action of the present invention is to provide a film that contributes to boundary lubrication that prevents the adhesion of metals in the most severe parts of the press while maintaining the press lubrication properties of the conventional fluid lubrication and solid lubrication film. To form. The constitution of the lubricating coating of the present invention will be described below. FIG. 1 shows a cross-sectional configuration diagram of the lubricated steel sheet of the present invention.

(A) is a schematic diagram of a three-layer film structure in which a chlorine-based boundary lubrication film is formed on the plating surface in advance and is coated with a chromate and a resin lubrication film, and (a) is a chromate film containing a chlorine-based lubricant. FIG. 2C is a schematic diagram of a two-layer coating structure included, and FIG. 3C is a schematic diagram of a two-layer coating structure in which a lubricating compound-containing resin film is coated on a chlorine-based lubricant-containing chromate film. In any case, the galling is prevented by the chlorine-based lubricating film formed on the metal surface during press working.

The respective coatings and components will be described below.
As the plated steel sheet, various cold-rolled and hot-rolled steel sheets can be applied. The surface roughness of the steel sheet can be used for both bright and dull finishes, but it is known that the roughness affects the lubrication performance, and it is desirable to manage the roughness within an appropriate range.

The plating film can be applied to galvanized steel sheets, zinc alloy plated steel sheets, and aluminized steel sheets manufactured by electric, melting, and vapor phase plating lines. The plating thickness can be applied to the normally produced 1 to 20 μm. The chlorine-based lubricant that controls the boundary lubrication action is composed of at least one kind of chlorinated fatty acid, chlorinated fatty acid ester, and chlorinated paraffin compound. In addition to preventing adhesion of the compound itself, this coating is chemically rich in lubricity and chemically reactive, and therefore chemically bonds to the new surface of the plated steel sheet generated during processing to prevent metal adhesion. Chlorinated fatty acids are compounds obtained by chlorinating fatty acids such as stearin. The chlorinated fatty acid ester is obtained by chlorinating a higher fatty acid ester, and the chlorinated fatty acid and the chlorinated fatty acid ester can be hydrophilized by using an amine or an alkali metal salt. Chlorinated paraffin is a chlorinated form of paraffin and is advantageous for addition to organic solvent-based resins. The chlorine content in each compound is preferably 20 to 60%.

The amount range of the chlorine-based lubricating coating is shown in FIG.
In the case of, Cl is 1 to 30 mg / m ² . Figure 1
In (a) and (c), the chromate and the resin are mixed and coated so that the total amount of the chlorine-based lubricant corresponding to (a) is 1 to 30 mg / m ² as Cl. Adhesion amount is 1m
If it is less than g / m ² , no significant improvement effect on galling is observed. If the adhered amount exceeds 30 mg / m ² , deterioration of corrosion resistance exceeds a practical level, which is not preferable.

The chromate film is an electrolytic and coating type chrome.
Coating is included in the present invention, but coating type chromate is desirable.
Good Chromate film is silica with chromic acid reduced
One or more of phosphoric acid and hydrophilic resin, and if necessary, described above.
A chromate solution containing a chlorine-based lubricant was applied and dried.
Chromate coating is desirable. Chromate adhesion is chromium
As 10-100 mg / m²Is the scope of the present invention.
Adhesion amount is 10 mg / m ²Is less than, the corrosion resistance is insufficient
100 mg / m²If it is super, the adhesion with the lubricating resin film is
It deteriorates and is not preferable.

The uppermost layer of the steel sheet of the present invention comprises silica resin 10
The resin film and the wax lubricant, which are contained in a proportion of 5 to 50 parts by weight in solid content relative to 0 parts by weight, are added to the resin in an amount of 5 to 5 parts by weight.
Lubricating resin coated with 2 to 25 parts by weight of a lubricating resin film as a base and 0.5 to 3.0 g / m ² as a dry adhesion amount of a film to which metal soap or an extreme pressure additive is added if necessary. It is a film layer.

As the resin used in the present invention, hydrophilic resins such as acrylic resins, epoxy resins, polyester resins, olefin resins, phenol resins, styrene resins and organic solvent resins can be applied, and if necessary, a curing agent such as melamine or amine is added. .. Since the effect of the present invention is great when a hydrophilic resin is used, its use is desirable. Silica is contained for the purpose of providing corrosion resistance, strength and toughness. If it is less than 5 parts by weight with respect to the resin, corrosion resistance cannot be obtained. If it exceeds 50 parts by weight, the workability of the coating deteriorates. The most preferred silica content is 10 to 30 parts by weight. Silica is preferably silica sol for hydrophilic resin, and dry silica is suitable for organic solvent-based resin. As for the shape of silica, a primary particle diameter of 2 to 50 nm and a secondary aggregate particle diameter of 100 nm or less are suitable. In the sol, the primary particles are dispersed almost completely, but the dry silica is agglomerated. In addition, there is a sol artificially grown into a non-spherical shape, for example, a linear shape, and is superior in quality to spherical silica in terms of adhesion, corrosion resistance, and the like.

Better lubricating performance can be achieved by adding a wax lubricant in a proportion of 5 to 25 parts by weight with respect to the resin. Lubricants added to the resin include various waxes, fatty acid soaps and extreme pressure additives. Of these, wax is most preferable in terms of lubrication and film properties. As the wax, polyolefin (polyethylene, polypropylene) or fluorine-based (polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride) can be used. If the content is less than 5 parts by weight with respect to the resin, a remarkable lubricating effect cannot be obtained, and if it exceeds 25 parts by weight, the corrosion resistance of the resin film and the adhesion of the topcoat paint are deteriorated, which is not preferable.

The amount of these lubricating resin coatings deposited is 0.5 to
It is in the range of 3.0 g / m ² . Adhesion amount is 0.5g / m ²
If it is less than the above range, the lubricity and corrosion resistance which are the objects of the present invention cannot be obtained. If the amount of the resin film adhered exceeds 3.0 g / m ^2, there is a problem that welding is impossible, which is not preferable. Each film is applied by a known method such as a roll coater, an air knife, electrostatic coating, and electrolysis, and is baked and cured by a known method such as hot air, infrared rays, induction heating, a gas furnace, and an electric furnace to manufacture.

[0018]

EXAMPLES The present invention will be described with reference to examples. The bath components in the examples have concentrations as non-volatile components. Example 1 As shown in Table 1, an amine-neutralized emulsion of chlorinated stearic acid having a chlorination rate of 30% was applied as a dry amount on the surface of an electrogalvanized nickel alloy-plated steel sheet containing 12% Ni and having a coating amount of 20 g / m ^2. It was applied and dried. Then, chromium reduction ratio (Cr ³⁺ / total Cr) 0.4 chromic acid 10 g / l
A coating type chromate aqueous solution containing 30 g / l of colloidal silica and a Cr coating amount of 20 mg / m ^{2 was} coated with a roll coater and dried at a plate temperature of 70 ° C. After cooling, 20 g by weight of a spherical silica sol (diameter 20 nm) was dispersed in 100 parts by weight of an olefin acrylic resin, and a dry coating amount of 1 g / m ^{2 was} applied to the resin coating, which was baked at a plate temperature of 120 ° C. in a hot air baking oven. After cooling with water, it was dried.

The coefficient of kinetic friction of the obtained resin-coated steel sheet and "galling" were evaluated by a square cylinder crank press.
The dynamic friction coefficient was obtained by applying a load of 1 kg to a steel ball having a diameter of 10 mm, moving the steel ball at 100 mm / min, measuring the tension (g) with a load cell, and calculating the tension / load. The conditions of the crank press are wrinkle suppression pressure of 6 tons and rough plate (0.8 × 22
0 x 180 mm) to 65 x 115 mm and height of 50 mm, peel off the side surface with adhesive tape and attach to imitation paper,
The lightness was measured with a color difference meter.

Corrosion resistance is 5% area ratio of white rust in salt spray test
The adhesiveness was evaluated by the time of occurrence, and a commercially available epoxy melamine resin paint was applied at a dry adhesion amount of 20 g / m ^{2 and} baked with hot air at 120 ° C. for 20 minutes, squeezed with a cross Erichsen 9 mm, and then peeled off with an adhesive tape. It was visually evaluated (peeled area ratio). The results are shown in Table 1. No. No. 1 is a sample of the present invention in which chlorinated stearic acid was applied on the plated surface at 10 mg / m ² , and Comparative Example No. No chlorinated stearic acid was applied in which corners with severe crank press characteristics and slight galling were observed on the side surfaces. Excellent results were obtained as compared with No. 4. No. In Nos. 2 and 3, the amount of chlorinated stearic acid applied was increased, and excellent crank pressability with little galling was exhibited. No. No. 3 had a slight decrease in paint adhesion.

[0021] Example 2 coating weight 20 g / m ² of the surface of the electrically zinc-nickel alloy plated steel sheet, amine-neutralized emulsion solution chlorination degree of 30% chlorinated stearic acid 3 g / l, chromium reduction ratio (C
A coating type chromate solution containing 10 g / l of chromic acid (r ³⁺ / total Cr) 0.4 and 30 g / l of colloidal silica was coated with a roll coater at the Cr deposition amounts shown in Table 2 and dried at a plate temperature of 70 ° C. .. After cooling, 20 parts by weight of spherical silica sol (diameter 20 nm) was added to 100 parts by weight of olefin acrylic resin, and 15 parts of polytetrafluoroethylene wax was also used.
The resin coating material dispersed in parts by weight was applied in a dry adhesion amount of 1 g / m ² , and was baked at a plate temperature of 120 ° C. in a hot air baking oven, cooled with water, and then dried. The evaluation was performed according to Example 1. The results are shown in Table 2.

No. Nos. 5, 6, and 7 are examples of the present invention in which a chromate solution containing an amine of chlorinated stearic acid is applied to the plating surface and a resin with a wax added is coated, and the friction coefficient is low, and the excellent results of almost no crank press galling are obtained. Indicated. No. No. 8 is a comparative example in which a chromate solution containing no amine of chlorinated stearic acid was applied, and galling occurred in a corner portion where processing was difficult.

Example 3 On the surface of an electrogalvanized steel sheet having a plating amount of 20 g / m ² ,
3 g / l of amine neutralized emulsion liquid of chlorinated stearic acid having a chlorination rate of 30%, and a chromium reduction ratio (Cr ³⁺ / total C
r) 0.4 g of chromic acid and 30 g of acrylic resin
/ L coating type chromate solution with a Cr deposit of 20 mg / m ²
Aiming at coating with a roll coater, it was dried at a plate temperature of 70 ° C. After cooling, linear silica sol (diameter 20 nm, length 50 n
2) to 100 parts by weight of olefin acrylic resin
0 parts by weight, 7 parts by weight of polyethylene wax dispersed in the same amount as a dry coating amount of 0.5, 1.0, 3.0
g / m ² coating and baking in a hot air baking oven at a plate temperature of 120 ° C.
After cooling with water, it was dried. The evaluation was performed according to Example 1.
The results are shown in Table 3.

No. Nos. 9, 10, and 11 are examples of the present invention in which the amount of the wax-added resin attached was 0.5, 1.0, and 3.0 g / m ² . No galling occurred in 10 and 11, N
o. Only the galling occurred in the corner portion of No. 9, and excellent crank pressability was exhibited.

Example 4 3 g / l of an amine-neutralized emulsion of chlorinated stearic acid having a chlorination rate of 30% and a chromium reduction ratio (C) were applied to the surface of an electrogalvanized nickel alloy-plated steel sheet having a plating amount of 20 g / m ^2.
Chromic acid 10 g / l of r ³⁺ / total Cr) 0.4 and coating type chromate solution of acrylic resin 30 g / l were used for the Cr adhesion amount of 20
mg / m ² Aiming at a roll coater with a plate temperature of 70
Dry to ° C. After cooling, the linear silica sol (diameter 20 nm,
20 parts by weight based on 100 parts by weight of an olefin acrylic resin, and a resin coating in which 15 parts by weight of polytetrafluoroethylene wax are dispersed in a dry adhesion amount of 1.0 g / m ^{2 and} applied in a hot air baking oven. Plate temperature 120
The product was baked at ℃, cooled with water and dried. The evaluation was performed according to Example 1. The results are shown in Table 3. As can be seen from No. 12, it shows extremely excellent crank pressability.

Example 5 An emulsion liquid of chlorinated oleic acid ester having a chlorination rate of 25% was applied to the surface of an electrogalvanized nickel alloy-plated steel sheet having a plating amount of 20 g / m ² as a nonvolatile content of 1 g / l and a chromium reduction ratio (Cr ^{3 +} / Total Cr) 0.4 chromic acid 10 g / l and linear silica sol (diameter 20 nm, length 50 nm) silica 3
0 g / l coating type chromate solution with Cr adhesion amount 60 mg /
A coating was performed with a roll coater aiming at m ² , and the plate was dried at a plate temperature of 70 ° C. After cooling, linear silica sol (diameter 20 nm, length 5
(0 nm) in an amount of 20 parts by weight per 100 parts by weight of an olefin acrylic resin, and a resin coating in which 15 parts by weight of polytetrafluoroethylene wax are dispersed in the same amount as a dry adhesion amount of 1.0 g / m ^{2 and} coated in a hot air baking oven. It was baked at a temperature of 120 ° C., cooled with water and dried. The evaluation was performed according to Example 1. The results are shown in Table 3. As can be seen from No. 13, it shows extremely excellent crank pressability.

Example 6 On the surface of an electrogalvanized steel sheet having a plating amount of 20 g / m ² ,
3 g / l of amine neutralized emulsion liquid of chlorinated stearic acid having a chlorination rate of 30%, and a chromium reduction ratio (Cr ³⁺ / total C
r) 0.4 g of chromic acid and 1 g of colloidal silica 3
A coating type chromate solution of 0 g / l was coated with a Cr coat amount shown in Table 4 by a roll coater and dried at a plate temperature of 70 ° C. After cooling, 20 parts by weight of spherical silica sol (diameter 20 nm) was added to 100 parts by weight of the aqueous emulsion resin shown in Table 4, and 15 parts of polytetrafluoroethylene wax was also used.
The resin coating material dispersed in parts by weight was applied in a dry adhesion amount of 1 g / m ² , and was baked at a plate temperature of 120 ° C. in a hot air baking oven, cooled with water, and then dried. The evaluation was performed according to Example 1. The results are shown in Table 4.

The present example is an example of the present invention regarding the kind of resin of the uppermost resin film, and No. No. 14 is a urethane epoxy resin, No. 14 15 is an example of ethyleneimine acrylic resin. Good results including pressability were obtained. No.
No. 16 is an example using a styrene acrylic resin, and the film was hard, and some galling occurred at the corners by the crank press. N
o. 17 is epoxy acrylic, No. 17 Reference numeral 18 is an example of the present invention using polyester. Good results were obtained in terms of pressability in general.

Example 7 On the surface of an electrogalvanized steel sheet having a plating amount of 20 g / m ² ,
3 g / l of amine neutralized emulsion liquid of chlorinated stearic acid having a chlorination rate of 30%, and a chromium reduction ratio (Cr ³⁺ / total C
r) 0.4 g of chromic acid and 1 g of colloidal silica 3
A coating type chromate solution of 0 g / l was coated with a Cr coater in the amount shown in Table 5 by a roll coater and dried at a plate temperature of 70 ° C.
After cooling, dry silica (primary particle size 20 nm, secondary particle size 5
(0 nm) is shown in Table 5 for 20 parts by weight per 100 parts by weight of the resin diluted with an organic solvent, 15 parts by weight of polytetrafluoroethylene wax and 3 parts by weight of chlorinated paraffin are dispersed in a resin coating material in a dry adhesion amount of 1 g. / M ² applied,
It was baked at a plate temperature of 150 ° C. in a hot air baking oven, cooled with water, and then dried. The evaluation was performed according to Example 1. The results are shown in Table 5.

In this embodiment, a resin dilutable with an organic solvent is used. No. Excellent press characteristics were obtained in which no galling occurred in any of 19, 20, 21, and 22.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

[0035]

[Table 5]

[0036]

EFFECTS OF THE INVENTION The steel sheet of the present invention does not need to use the chlorine-based solvent used for removing the press oil, contributes to the prevention of environmental pollution, and saves labor because the work process is simplified.
It has the effect of enhancing the working environment. In addition, since it has excellent corrosion resistance, it is possible to omit the step of coating which is conventionally performed after processing.

[Brief description of drawings]

FIG. 1 is a schematic view showing a constitutional view of a film of the present invention.

Claims (2)

[Claims] 1. The surface of a plated steel sheet is 10 to 1 in terms of Cr.
Resin 1 with a chromate film of 00 mg / m ² and silica
0.5 to 3.0 g as a dry adhesion amount of a resin film containing 5 to 50 parts by weight of solid content with respect to 00 parts by weight.
In / m ² coated with the resin-coated plated steel sheet, chlorinated fatty acids, chlorinated fatty acid esters, or coated on the lower layer of 1 to 30 mg / m ² chromate film of one or more chlorinated paraffins compound as Cl adhesion amount, or chromate A surface-treated steel sheet with excellent deep drawability that is contained in the coating. 2. The surface of the plated steel sheet has a Cr content of 10 to 1
Resin 1 with a chromate film of 00 mg / m ² and silica
Resin coating in which 0.5 to 3.0 g / m ² as a dry adhesion amount of a resin coating containing 5 to 50 parts by weight of solids and 5 to 25 parts by weight as a solid content with respect to 00 parts by weight is coated. In the plated steel sheet, one or more kinds of chlorinated fatty acid, chlorinated fatty acid ester, and chlorinated paraffin compound are coated as a Cl adhesion amount in the lower layer of the chromate film of 1 to 30 mg / m ² or contained in the chromate film. A surface-treated steel sheet with excellent deep drawability.