JP2000107669A - Continuous surface treatment equipment for steel strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute plural kinds of surface treatments with the same surface treatment stage. SOLUTION: This surface treatment equipment is successively provided with a galvanizing device 1/an electrolytic chromate treatment device 2, a washing device 3 and a coating type chromate treatment device 4 and is further successively provided with a resin coating application device 9, a drying device 11 and a cooling zone 12 in a perpendicular direction above this coating type chromate treatment device 4. As a result, the surface treatments of plural kinds may be executed with the same surface treatment stage and even more, the surface treatment may be executed with a small space by the passing of the strip in a horizontal direction and the passing of the strip in an upper perpendicular direction. In addition, the uniform application of the resin film is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for continuously treating steel strip.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 61-57263 discloses a continuous surface treatment method for a steel strip, in which a coating material or the like is applied by vertically passing through a sheet (vertical sheet passing).

[0003]

As described above, in the continuous surface treatment method for steel sheets (bands), there are restrictions on the types of products to be switched due to the physical properties of the coating agent, and it takes a long time to change the types and the productivity is reduced. At the same time, the operation switching becomes complicated and labor saving is difficult. In addition, since it is a vertical type passing plate, there is a problem that the applied coating material after coating has irregularities in the sagging appearance color tone and deteriorates the quality. The present invention has been made to advantageously solve such a problem, and easily and quickly switches the surface treatment type (coating agent) on the same line to produce various types of surface treatment steel strips (plates). Continuous surface treatment of steel strips, such as manufacturing, keeping the space of the line in a small area, and also preventing the sagging of the coating after coating and suppressing the appearance unevenness during the vertical pass-through coating. The purpose is to provide facilities.

[0004]

A feature of the present invention is that, in the first invention, a zinc-based plating apparatus, an electrolytic chromating apparatus, a washing apparatus, and a coating type chromate processing apparatus are connected in a horizontal direction. A continuous steel strip surface treatment facility comprising a resin coating device, a drying device, and a cooling zone connected in a vertical direction above the coating type chromate processing device. According to a second aspect of the present invention, an annealing apparatus for steel strip, an electrolytic chromating apparatus, a rinsing apparatus, and a coating type chromate processing apparatus are connected in a horizontal direction, and a resin coating apparatus and a drying apparatus are arranged vertically above the coating type chromate processing apparatus. -A continuous surface treatment equipment for steel strips, characterized by connecting cooling zones continuously. According to a third aspect of the invention, an electrolytic chromating apparatus, a washing apparatus, and a coating type chromate processing apparatus are connected in a horizontal direction, and a resin coating apparatus, a drying apparatus, and a cooling zone are connected in a vertical direction above the coating type chromate processing apparatus. This is a continuous treatment facility for steel strips.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first invention as described above, an electrogalvanizing apparatus or a hot-dip galvanizing apparatus, an electrolytic chromating apparatus, a water washing apparatus, and a coating type chromate processing apparatus are sequentially connected in the horizontal direction. The steel strip is transferred to an electro-galvanizing apparatus or a hot-dip galvanizing apparatus by a continuous surface treatment equipment (line) in which a resin coating apparatus, a drying furnace, and a cooling zone are sequentially connected vertically above the coating type chromate processing apparatus. For example, a zinc-based plating such as zinc, a zinc-iron alloy, a zinc-nickel alloy, a zinc-aluminum alloy, and a zinc-chromium alloy is plated to a coating amount according to the use of the product.

[0006] Such a galvanized steel strip is led to an electrolytic chromate treatment apparatus, and about 20 mg
/ M ² (as the amount of chromium) is coated with an electrolytic chromate film to increase the corrosion resistance and the adhesion of the resin film afterwards, and then remove the remaining electrolytic chromate treatment solution by washing with water. (Zinc-coated steel strip after electrolytic chromate treatment at a high temperature)
By heating to 80 ° C., a part of the moisture in the resin coated on the upper layer of the electrolytic chromate film is evaporated, and the applied resin is slightly cured to prevent dripping of the applied resin and to suppress color tone unevenness in appearance. In addition to heating the galvanized steel strip as described above, it is also possible to heat between the inlet sides of the resin coating device after the electrolytic chromate treatment.

[0007] The zinc-plated steel strip which has been subjected to the electrolytic chromate treatment and heated is guided to a coating type chromate treatment apparatus, and without applying the coating type chromate treatment (the chromate treatment liquid in the chromate treatment tank is discharged to pass the plate. ) The sheet is passed through the plate vertically upward and guided to the resin coating device.

Thus, for example, an acrylic resin having a thickness of 0.5 to 3.0 μm is applied as a thermosetting resin to the upper layer of the electrolytic chromate film of the galvanized steel strip coated with the electrolytic chromate film, depending on the application. When applying the resin, the steel strip is applied while being passed vertically upward, so that vibration occurs in the steel strip, and the application of the resin becomes uneven. Thus, if the contact pressure of the application roll to the steel strip is increased to prevent the vibration of the steel strip, the vibration can be prevented, but the threaded steel strip slips on the contact surface of the application roll, and the application of the resin becomes impossible. Become uniform. In order to surely eliminate such difficulties, the surface of the application roll is set to Ra 0.8 to 1.2, and the resin is applied at a peripheral speed of 1.5 to 3.0 times the passing speed of the application roll. By doing so, the contact pressure to the steel strip can be reduced to prevent vibration and also prevent slipping, so that the resin can be applied uniformly.

The reason why the coating roll surface roughness and the coating roll peripheral speed can prevent the steel strip from vibrating and prevent slipping so that the resin can be uniformly coated is as follows. Are thinking. The vibration of the steel strip can be reduced by increasing the rolling force of the application roll, but on the contrary, the roll slip tends to occur. On the other hand, roll slip can be improved by lowering the rolling force, lowering the coefficient of friction between the roll and the steel strip, and increasing the relative speed between the roll and the steel strip. By reducing the coefficient of friction between the roll and the steel strip (for example, reducing the surface roughness of the roll) and increasing the relative speed between the roll and the steel strip (for example, increasing the peripheral speed of the roll) within a range in which problems such as coating unevenness do not occur. In addition, it is possible to raise the critical rolling force at which slip occurs and to operate with a rolling force capable of suppressing the vibration of the steel strip.

[0010] In this way, the zinc-based galvanized steel strip having the resin applied to the upper layer of the electrolytic chromate film is led to a drying furnace,
The steel strip is heated to a temperature of 100 to 200 ° C. and then cooled to 80 ° C. or less to obtain a galvanized steel strip having a corrosion resistant and beautiful surface treatment.

[0011] In addition to the surface treatment as described above, a zinc-based plated steel strip obtained by applying a zinc-based plating to a steel strip as described above is passed horizontally without passing through an electrolytic chromate treatment apparatus. With a coating type chromate treatment device, the surface is immersed and passed through a coating type chromate treatment solution, and about 1 kg
/ Cm ² gas injection to adjust the amount of treatment liquid attached,
For example, after coating a coating type chromate film of about 20 mg / m ² (as the amount of chromium), it is led to a drying device without coating the upper layer with a resin by a resin coating device, and is heated to about 100 ° C.
, And then cooled in a cooling zone to produce a galvanized steel strip (plate) that has been subjected to surface treatment with excellent corrosion resistance. Thus, by separately producing high efficiency and different surface treatment steel strips in the same equipment (line), a plurality of processing equipment (lines) is not required, and furthermore, with the horizontal and upward vertical equipment configuration, It can be configured with a small range of space.

[0012] In the second invention, the steel strip is annealed by an annealing apparatus, then coated with an electrolytic chromate film as described above, and a resin is applied to the upper layer, and the steel strip is annealed. The surface is subjected to a surface treatment for coating with a coating type chromate film, and is divided into surface-treated steel strips (plates) exhibiting the same performance.

In the third aspect of the invention, the production of a zinc-based steel strip or the annealing treatment of the steel strip is performed in a separate step (line), and as described above, the electrolytic chromate film is coated, and the resin is rolled on the upper layer. A zinc-based alloy that can achieve the same performance by applying a surface treatment to apply and a surface treatment to apply a coating-type chromate film to the surface of a galvanized steel strip or an annealed steel strip manufactured in a separate process (line). Separate into plated steel strip (plate) or steel strip.

[0014]

Next, examples of the method of the present invention will be described. Example 1 In FIG. 1, a gas was supplied in the horizontal direction to the output side of an electro-galvanizing apparatus or a hot-dip galvanizing apparatus, a zinc-based plating apparatus 1, an electrolytic chromate treatment apparatus 2, a washing apparatus 3, and a coating type chromate treatment apparatus 4. An injection nozzle 5 is provided, and a resin coating device (a resin coating device including a coating roll 8 and a resin pickup roll 7) 9-drying device (a gas that shuts off the accompanying air on the entrance side) is provided vertically above the coating type chromate treatment device 4. Drying furnace with injection nozzle 10) 11-cooling zone 1
In the surface treatment equipment provided with 2 in parallel, while passing the steel strip 13 in the horizontal direction, the zinc-based plating apparatus 1 performs zinc-based plating,
The zinc-plated steel strip 13a is coated with an electrolytic chromate film by the electrolytic chromate treatment device 2, and then the zinc-plated steel strip 13a coated with the electrolytic chromate film is washed with a water washing device 3.
The washing device 3 includes a heating device 14 (heat exchanger).
A zinc-based material that can remove a small amount of moisture in the applied resin applied to the surface of the later-described electrolytic chromate film-coated zinc-based plated steel strip 13a and cures the resin depending on the temperature of the washing water to prevent dripping of the resin. The coated steel strip 13a is heated to the temperature at the same time as washing with water. Next, coating type chromate treatment device 4
Without passing through the chromate treatment, the zinc-plated steel strip 13a coated with the electrolytic chromate film is guided to the resin coating device 9 by passing the plate vertically upward from the coating type chromating device 4,
The resin is applied by bringing it into contact with the application roll 8, then dried in a drying furnace 11, and then cooled in a cooling zone 12 to perform a surface treatment for producing a product.

When coating the zinc-based plated steel strip 13a with a coating type chromate film, the zinc-based plating is performed by the zinc-based plating apparatus 1 while passing the steel strip 13 in the horizontal direction.
It is led to the electrolytic chromating device 2 and the washing device 3, passed through the plate without performing electrolytic chromating and water washing, immersed and passed into the coating type chromate treatment liquid by the coating type chromate treatment device 4, and the gas injection nozzle 5 A coating type chromate film is coated by adjusting the amount of adhesion by injecting a gas from the substrate. Next, the resin is passed through the resin coating device 9 without applying the resin, dried in the drying furnace 11, and then cooled in the cooling zone 12.

Embodiment 2 In FIG. 2, a steel strip 13 is subjected to an annealing treatment apparatus (annealing furnace) 14.
Then, after coating the electrolytic chromate film with the electrolytic chromate treatment device 2 as in Example 1 above, the steel strip 13 is heated by the washing water heated by the heat exchanger 14 while being washed with the water washing device 3. Then, the steel strip 13 coated with the electrolytic chromate film is passed vertically upward from the coating type chromate apparatus 4 without performing the chromate treatment with the coating type chromate treatment apparatus 4 to apply the electrolytic chromate film coated steel strip 13 to a resin coating step. 9, the resin is applied by bringing it into contact with the application roll 8, then dried in the drying furnace 11 and then cooled in the cooling zone 12.
Surface treatment to cool and produce the product. Further, when coating the steel strip 13 with the coating type chromate film, the steel strip 13 is annealed in an annealing device (annealing furnace) 14 while passing the steel strip 13 in the horizontal direction, and guided to the electrolytic chromating device 2 and the water washing device 3, After passing through the plate without performing the electrolytic chromate treatment and washing with water, the coated plate is immersed and passed into the coating type chromate treatment liquid by the coating type chromate treatment device 4, and the gas is injected from the gas injection nozzle 5 on the outlet side to adjust the adhesion amount. To coat the coating type chromate film. Next, the resin is passed through the resin coating device 9 without applying the resin,
After drying in the drying furnace 11, it is cooled in the cooling zone 12.

Embodiment 3 In FIG. 3, the production or the annealing treatment of the galvanized steel strip 13a is carried out in a separate step (line), and as described above, after the electrolytic chromate film is coated by the electrolytic chromate treatment apparatus 2, The washing water heated by the heat exchanger 14 at the same time that the electrolytic chromate film-coated zinc-based galvanized steel strip 13a or the electrolytic chromate film-coated steel strip is heated by the washing water heated by the heat exchanger 14 while being washed with the water washing device 3. After heating, the coating type chromating device 4 can be used without subjecting the coating type chromating device 4 to chromate treatment.
From above, the electrolytic chromate film-coated zinc-coated steel strip 13a or the electrolytic chromate film-coated steel strip 13a is guided to a resin coating device 9, which is brought into contact with a coating roll 8 to apply the resin, and then a drying furnace After drying at 11, cooling zone 12
Surface treatment to cool and produce the product. When the coating type chromate film is coated on the galvanized steel strip 13a or the annealed steel strip manufactured in another process (line), the steel strip 1
3a is guided horizontally to the electrolytic chromating apparatus 2 and the washing step 3 while being passed horizontally, and is passed without being subjected to electrolytic chromating and water washing, and is immersed and passed into the coating type chromate treatment liquid by the coating type chromate treatment apparatus 4. Then, a gas is injected from the gas injection nozzle 5 on the outlet side to adjust the amount of adhesion and coat the coating type chromate film. Subsequently, the resin is passed through a resin coating device 9 without applying the resin, and dried in a drying furnace 11.
It cools down.

Operation Example Next, an operation example using the facility of the present invention will be described together with a comparative example.

[Table 1]

[0019]

[Table 2] (continuation of Table 1)

[0020]

[Table 3]

[0021]

[Table 4] (continuation of Table 3)

Note 1: Odd numbers in both the operation example and the comparative example are as follows:
After coating the electrolytic chromate film, apply resin on the upper layer, and even-numbered examples apply a coating type chromate film. Note 2: Operation examples 1, 2, 3, and 4 are examples of the first embodiment. Operation examples 5 and 6 are examples of the third embodiment. Operation examples 7 and 8 are examples of the first embodiment. Operation examples 9 and 10 are examples of the third embodiment. Operation examples 11 and 12 are examples of the second embodiment. Operation examples 13 and 14 are examples of the third embodiment. Note 3: Steel strip type EZ is electro-galvanized steel strip. EZS
Is an electric zinc-iron alloy (iron 12%, remaining zinc) plated steel strip. EZN is an electric zinc-nickel alloy (nickel 5
%, The rest zinc) plated steel strip. GZ is a hot-dip galvanized steel strip. GZA is a hot-dip zinc-aluminum alloy (5% aluminum, remaining zinc) plated steel strip. Note 4: Electrolytic Cr is coated (as chromium amount) on the electrolytic chromate film with a commonly used electrolytic chromate treatment solution. Note 5: The temperature of the steel strip after washing is the temperature at which the steel strip is heated by the heat of the washing water at the same time as the washing after electrolytic chromate treatment. Note 6: coating type Cr is generally used has been that a coating type chromating solution by (CrO ₃ -SiO ₂ system), a coating type chromate film (as chromium amount) coating. Note 7: The coating roll peripheral speed ratio for resin coating is the ratio (magnification) of the steel strip passing speed. Note 8: The contact pressure of the application roll for resin application is 200 kg / m
(Kg / m-width length). Note 9: The resin application roll is a 20 mm thick urethane resin coating on the metal roll surface. Note 10: The sagging of the applied resin is based on the presence or absence of sagging of a part of the resin after application (○: no sagging, Δ: slight,
X: Color tone deterioration due to sagging). Slip unevenness is caused by slippage of the threaded steel strip on the contact surface of the resin application roll and uneven application because the resin cannot be applied uniformly (（: no unevenness, Δ: slightly present, ×:
Intermittent color deterioration). Vibration non-uniformity is caused by non-uniformity of the applied resin due to vibration at the resin application position on the continuous steel strip (○:
No unevenness, Δ: generated intermittently, ×: constantly generated color tone deterioration). Note 11: Drying burns coke oven generated gas. Cooling is
Steam cooling. Note 12: The running speed is 50 to 250 m / min.

[0023]

According to the equipment of the present invention, a plurality of types of surface treatment can be performed in the same surface treatment step, and furthermore, the surface treatment can be performed in a small space by the horizontal passing and the vertical passing. In addition, excellent effects such as the resin film being uniformly applied and the quality being improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of the facility of the present invention.

FIG. 2 is a flowchart showing an example of the facility of the present invention.

FIG. 3 is a flowchart showing an example of the facility of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 zinc-based plating device 2 electrolytic chromate treatment device 3 water washing device 4 coating type chromate treatment device 9 resin coating device 11 drying device 12 cooling zone 13 steel strip 13a zinc-based plating steel strip

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Makoto Ueda 5-3 Tokai-cho, Tokai-shi, Aichi F-term in Nagoya Works, Nippon Steel Corporation (reference) 4F042 AA22 DA01 DA02 DB00 DC00

Claims (5)

[Claims] 1. A zinc plating apparatus, an electrolytic chromating apparatus, a washing apparatus, and a coating type chromate processing apparatus are connected in a horizontal direction, and a resin coating apparatus, a drying apparatus, and a cooling apparatus are provided vertically above the coating type chromate processing apparatus. Continuous surface treatment equipment for steel strips, characterized by a series of strips. 2. An annealing apparatus for a steel strip, an electrolytic chromating apparatus, a washing apparatus, and a coating type chromate processing apparatus are connected in a horizontal direction, and a resin coating apparatus and a drying apparatus are arranged vertically above the coating type chromate processing apparatus. Continuous surface treatment equipment for steel strip, characterized by connecting cooling zones. 3. An electrolytic chromate treatment device, a washing device, and a coating type chromate treatment device are connected in a horizontal direction, and a resin coating device, a drying device, and a cooling zone are connected in a vertical direction above the coating type chromate treatment device. A continuous surface treatment facility for steel strips. 4. The washing device according to claim 1, wherein the washing device is provided with a washing water heating device.
2. A continuous surface treatment equipment for steel strip according to item 1. 5. The resin coating device according to claim 1, wherein a resin coating roll having a surface roughness Ra of 0.8 to 1.2 is attached to the resin coating device. Steel strip continuous surface treatment equipment.