JPH02111853A - Continuous plating equipment for metal sheet - Google Patents

Abstract

PURPOSE:To remove the problems due to the use of a molten metal bath by providing a device for supplying a plating metal material in a solid phase to a metal sheet, a device for heating and melting the above metallic material, and a molten metal-feeding nozzle and carrying out plating while melting the above metallic material by the quantity equivalent to coating weight. CONSTITUTION:A plating metal material 4 in a solid phase is supplied by means of a supply mechanism 1 in the direction of a passing metal sheet S. The end of the above metallic material 4 is successively melted at the position right before the metal sheet S by means of a heating and melting device 2. The resulting molten plating metal 14 is supplied onto the surface of the metal sheet S through a supply nozzle 3 in which the width of a nozzle hole in a line direction is variably constituted. By this method, a plating film 17 can be easily formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus capable of continuously plating the surface of a metal plate without using a molten metal bath.

[Conventional technology]

Conventionally, as a method for forming a plating film on the surface of steel strip,
Hot-dip plating is a widely used method in which a steel strip is immersed in pre-molten plated metal.

In continuous hot-dip galvanizing, which is a typical example of this type of plating method, the steel strip is heat-treated and surface-cleaned in a pre-treatment furnace, and then immersed in a hot-dip zinc bath to form a plating film.
The steel strip pulled out from the bath is subjected to plating coating amount adjustment by gas throttling and surface conditioning such as galvanealing.

The hot-dip plated steel sheet thus obtained has a relatively beautiful surface and excellent corrosion resistance, so it is widely used in practical applications.

However, conventional hot dip galvanizing methods have various problems associated with the use of plating baths. Particularly recently, plated steel strips are required to have a more uniform, smooth, and beautiful surface than ever before, mainly for use in home appliances, automobile exterior panels, etc. There is also a high demand for new products such as, and as a result, problems with the quality of plated steel strips and the plating process itself using conventional hot-dip plating methods have become apparent. Some of such problems are discussed below.

l) Fe from the surface of the steel strip is eluted in the plating bath, and so-called dross is often generated due to the oxidation of the plating metal, and this must be pumped up and removed. A loss of plated metal occurs.

2) Impurities are likely to be mixed into the plating bath, such as dross being generated in the plating bath and debris from the bricks that make up the pot being mixed into the bath, and these will adhere to the fR band and deteriorate its appearance.

3) Since the components of the plating metal ingot put into the bath are different from the trace elements in the components that adhere to the steel strip and the components that are discharged outside the bath as by-products such as dross, the necessary elements are contained as per the target. It is difficult to adjust and control the plating bath components.

As a result, various plating defects occur, such as poor plating adhesion and poor alloying of the galvanic material.

4) It is necessary to immerse steel mechanical parts such as rolls for threading copper strips, roll support arms, bearings, etc. in a high temperature, highly corrosive plating metal bath.

This causes problems such as erosion of these members, generation of dross accompanying this, and deterioration of the appearance of the plating surface due to erosion of the surface of the roll in the bath.

Furthermore, operation downtime is required to periodically repair or replace eroded or damaged parts of these mechanical parts, making it impossible to effectively and maximally utilize the production capacity of the equipment.

5) By using a passing roll in the plating bath, the group grooves of the roll are likely to be transferred to the plating surface, resulting in deterioration of the appearance.

6) Discharge of bottom dross that accumulates at the bottom of the column, top dross that accumulates on the bath surface, initial threading of copper strips into the bath, maintenance of rolls in the plating bath, etc., at high temperatures and in large quantities. Working near the plating bath places a heavy burden on the worker and is dangerous.

7) Pot - Since only one type of plating can be done per group,
When performing various types of dissimilar plating, it is necessary to carry out routine practice by pumping out a bath, or to prepare in advance a pot in which dissimilar plating metals are melted, and to move the pot.

8) When producing double-sided plated materials and single-sided plated materials in a single facility, it is necessary to change the plating equipment for the pot section, which requires a lot of time and effort in addition to the equipment burden. .

9) It is difficult to perform special plating such as double-sided dissimilar plating, multilayer plating, and double-sided differential thickness plating.

In contrast to such conventional hot-dip plating methods, JP-A-61-2
In No. 07555, etc., a nozzle is brought close to the surface of the running #A strip, and the molten metal supplied from the molten metal tank is sucked out from the nozzle by the wet adhesive force between the molten metal and the steel strip surface, and is made to adhere to the copper strip. A new plating method has been proposed.

This method applies coating technology for high-viscosity paint, etc., but the molten metal is fed from the molten metal tank to the nozzle, and the amount of plating deposited is controlled by the head pressure of the molten metal tank. Therefore, a change in the height of the bath surface in the tank results in variations in the amount of plating deposited, and this has the disadvantage of poor accuracy in the amount of plating deposited. Furthermore, in any case, since a molten metal bath corresponding to an immersion type plating bath is required, there are various problems as described above.

As described above, conventional hot-dip plating methods have had various problems.

In order to solve these problems, the present inventors have developed a new method that can continuously apply hot-dip plating to a metal plate without using a molten metal bath first, and can control the coating amount with high precision. Patent application 1986-10330 for plating method
I proposed this as number 2.

This method uses solid phase plating metal materials (4
) is continuously fed toward the surface of the moving metal plate (A), and the tip side of the plated metal material (4) is moved toward the surface of the metal plate (A).
sequentially melted by a heating melting device (15) facing the
This is a method in which molten plated metal (14) is continuously deposited on the surface of a metal plate from a supply nozzle (16) as a plated film (17).

[Problem to be solved by the invention]

By the way, in this plating method, the plating metal supply rate from the nozzle is determined by the line speed x the amount of plating deposited, and therefore the supply rate changes greatly depending on the line speed and the amount of plating deposited. For example, when the line speed is 2 m/s and the amount of plating deposited is 10 g/m (unit width, the same applies hereinafter), the supply speed of the plating metal is 20 g/s, while the When the amount is 90 g/m, the feed rate is 270 g/s, and the difference between the two is more than 10 times.The feed nozzle (16) has a nozzle opening width ( It is necessary to make the aperture width (in the line direction) wide to some extent, but if the aperture width is increased, plated metal may be partially supplied from the nozzle opening due to defective plate shape or displacement due to plate vibration. This causes plating defects to occur.

In view of these problems, the present invention enables hot-dip plating to be continuously applied to a metal plate without using a molten metal bath.
Moreover, the present invention aims to provide an apparatus that can stably supply molten plated metal to a metal plate through which it passes, depending on the line speed and the amount of coating.

[Means to solve the problem]

For this reason, the present invention includes a supply mechanism that supplies a solid-phase plated metal material toward the surface of a metal plate through which the plate is passed, and a heating melting device that melts the supplied plated metal material immediately before the metal plate. The melting device has a supply nozzle facing the metal plate passing line that supplies molten plated metal to the metal plate surface and deposits it as a plating film, and the supply nozzle has a variable nozzle opening width in the line direction. It is characterized by being composed of.

[For production]

According to the apparatus of the present invention, the supply mechanism continuously supplies the solid-phase plated metal material to the surface of the metal plate through which it passes. The supplied plated metal material is melted in front of the metal plate by a heating melting device, and this molten plated metal is supplied from a supply nozzle to the surface of the metal plate through which the plate passes, and adheres to the metal plate as a plating skin (1!4).

The nozzle opening width of the supply nozzle is adjusted according to the line speed and the amount of coating, and is set to an appropriate nozzle opening width according to the plating metal supply speed.

〔Example〕

FIG. 2 shows an embodiment in which the present invention is applied to continuous galvanizing treatment of steel strip.

The apparatus (a) of the present invention includes a feeding mechanism (1) for plating metal material (zinc plate), melting the supplied plating metal material just before the steel strip, and melting the supplied plating metal material onto the surface of the copper strip passing through the nozzle. It has a heating melting device (2) etc. for supplying the water.

The supply mechanism (1) is for feeding the solid-phase plated metal material in the direction of the copper strip (in this embodiment, the direction perpendicular to the steel strip), and in this embodiment, the plate-shaped plated metal material is fed through the copper strip. It is composed of feed rollers (5) that pinch the copper strip (4) from both sides and feed it in the direction of the copper strip.

This feeding mechanism (1) is not limited to a pinch roller, and any suitable feeding mechanism using a cylinder device, electric motor, etc. can be used, for example.

The heating melting device (2) melts the supplied plated metal material just before the surface of the copper strip, and in this embodiment, it is a cylindrical body with an elongated cross section ( 6). Further, a preheating device (8) for plating metal material is provided upstream of the heating and melting device (2) in the direction in which the plating metal material is supplied.

Note that the configuration of the heating melting device (2) is not limited to the above embodiment, and any heating method, structure, etc. may be used as long as it has a nozzle close to the surface of the copper strip.

A supply nozzle (3) for supplying molten plated metal is formed at one end side facing the steel strip of the cylindrical body (6) constituting the heating melting device.

This supply nozzle (3) is configured to have a variable nozzle opening width in the direction of the copper strip threading line, and in this embodiment, a shielding plate ( 9) is provided, and the nozzle opening width can be changed by this shielding plate (9).

In the map, (10) is a surface conditioning device for making the formed plating film uniform. The formed plating film may have slight unevenness in coating amount due to vibrations of the steel strip, etc., and in order to make this unevenness uniform, it is possible to perform a uniformization treatment using the above-mentioned surface conditioning device (10). . As this surface conditioning device (10), for example, an ultrasonic vibration type device (so-called ultrasonic iron) having an ultrasonic vibrator is used. This device is held by a cylinder device (not shown) having a loose 1fi mechanism, and its diaphragm is brought into light contact with the surface of the steel strip on which the plating film is formed, thereby applying ultrasonic vibration to the plating film. This makes the film thickness of the plated metal uniform.

In addition, (11) is a pinch roll that pinches the metal plate on the upstream side of the plating part in order to prevent uneven plating adhesion caused by the vibration of the metal plate. ) and the supply nozzle (3) or the shielding plate (9) can also be prevented.

The pinching position of the steel strip by the pinch rolls (11) should be as close as possible to the contact area of the plated metal material (4), and usually within 2000 mm (more preferably within 500 mm) from the contact area in the longitudinal direction of the copper strip. It is preferable to do so.

As a means (pinch means) for preventing uneven adhesion due to vibration of the copper strip, it is possible to use not only the above-mentioned pinch roll but also an air action method, an electromagnetic force method, or other suitable means.

Figure 3 shows the width of the nozzle opening! l! This shows another example in which the 1 m mechanism is different, in which the cylindrical wall (61) on the downstream side in the copper band passing direction of the cylindrical body (6) constituting the heating melting device (2) is connected via the hinge (12). It is configured to be rotatable and is held at a predetermined angle by a holding means (13) such as a cylinder device. By adjusting the angle of the cylindrical wall (61) as described above, the nozzle opening width of the supply nozzle at one end of the cylindrical body can be adjusted.

Note that the other configurations are the same as those shown in FIG. 2.

Note that the nozzle opening width adjustment mechanism is not limited to that shown in FIGS. 2 and 3.

For example, the front and rear walls of the nozzle tip may have a flexible structure, and the nozzle mouth width may be narrowed by pushing the front and rear walls with a cylinder device or the like.

Next, how to use the device as described above will be explained.

Depending on the line speed and amount of coating, the shielding plate (9) can be moved in the case of Fig. 1, and the rotation angle of the cylinder wall (61) can be adjusted in the case of Fig. 2 to prevent unplated coating. Adjust the nozzle opening to the appropriate convergence so that there is no partial or large plating distribution.

The solid phase plated metal material (4) is supplied by the supply mechanism (1) in the direction of 11 belts (S) through which the plate passes. Plated metal material (
4) is preheated by a preheating device (8), and then the tip side is sequentially melted by a heating melting device (2), and the molten plated metal (14) is supplied to the steel strip surface from a supply nozzle (3),
A plating film (17) is formed.

Plated metal materials (4) are sequentially charged into the supply mechanism (1) by appropriate means and are bitten by the feed roller (5). Then, this plating metal material (4) is sent to the surface of the copper strip by a feed roller (5) in an amount commensurate with the amount consumed for plating.

Although the plated metal material (4) is a plate material in this embodiment, powdered plated metal material may be sequentially supplied depending on the case. In this case, for example, the supply cylinder is filled with powdered plating metal material, and this is pressed and moved in the direction of the steel strip by a suppressing mechanism such as a cylinder device.

With the apparatus of the present invention, the steel strip (S) can be plated at room temperature, but in that case, the sudden rise in temperature of the steel strip due to contact with molten metal causes non-uniform thermal expansion of the strip, causing the strip shape to change. In order to prevent this, there is a risk of defects.
Preferably, the steel strip (S) is preheated to a predetermined temperature and the copper strip is plated. Although this preheating temperature is not particularly limited, it is preferable to set it to a preheating temperature around the melting point of the plated metal material (4).

In addition, the plating process using the apparatus of the present invention is performed in a non-oxidizing atmosphere (for example, H
It is preferable to carry out the reaction in a mixed gas of 2:20 to 25% and N2: 80 to 75%. Further, it is preferable that the surface of the steel strip before plating is as clean as possible.

Plating by the apparatus of the present invention can be applied to various metal or alloy platings, for example, Zn plating of steel strips,
Including AQ-Zn alloy plating, Co-Cr-Zn
Alloy plating (e.g. 1%Co-1%Cr-Zn alloy plating), AQ-ME-Zn alloy plating (e.g. 5%i
-0.6%Mg-Zn alloy plating), AM-5
i-Zn alloy plating (e.g. 55% Al1-1.6
%5iZn alloy plating), 5i-Al1 alloy plating (for example, 10% Si-Al alloy plating), 5n-Pb alloy plating (for example, 10% Sn-Pb alloy plating), etc.

Further, when double-sided plating of a steel strip is performed using the apparatus of the present invention, each plating does not necessarily have to be performed at the same position in the line direction. Furthermore, in the present invention, it is also possible to run the steel strip (S) in a direction other than horizontally, for example, in a vertical direction. In the case of this vertical line, the running direction may be either up or down.

〔Effect of the invention〕

According to the present invention described above, the melting device facing the metal plate through which the solid-phase plated metal material is passed melts the amount corresponding to the plating area immediately before the surface of the metal plate, and adheres this to the metal plate as a plating film. For,? 8. Molten metal plating of metal plates can be performed without the need for a molten metal bath at all, all the conventional problems caused by the use of molten metal baths can be solved, and the nozzle in the direction of metal plate threading can be applied. Since the opening width can be changed, plated metal material can be stably supplied depending on the line speed and coating amount.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the hot-dip plating method on which the present invention is based. FIGS. 2 and 3 are explanatory diagrams showing embodiments of the present invention, respectively. In the figure, (1) a supply mechanism, (2) a heating melting device,
(3) is a supply nozzle. Figure 1

Claims (1)

[Claims] It has a supply mechanism that supplies a solid phase plated metal material toward the surface of the metal plate to be passed, and a heating melting device that melts the supplied plated metal material just before the metal plate, and the heating melting device A supply nozzle facing the plate line that supplies molten plated metal to the metal plate surface and deposits it as a plating film, the supply nozzle having a variable nozzle opening width in the line direction. Continuous plate plating equipment.