JPH01279767A - Method for continuously plating metallic sheet - Google Patents

Abstract

PURPOSE:To continuously plate a metallic sheet with high precision while controlling a plating amt. by bringing a plating metal into contact with the moving sheet heated to a specified temp. so that the metal receives a constant reaction force from the sheet, and continuously supplying the metal to the sheet. CONSTITUTION:The plating metal 2 is brought into contact with the moving metallic sheet 1 heated to a temp. higher than the m.p. of the plating metal and melted, and the molten metal 2 is continuously supplied to the sheet 1. The layer 3 of the molten metal 2 is continuously deposited on the moving sheet 1 as a film 4. The sheet 1 is continuously plated in this way. In this case, the metal 2 is pressed on the sheet 1 so that the metal 2 always receives a constant reaction force from the sheet 1. The supply rate of the metal 2 is controlled, and the plating amt. can be controlled with high precision.

Description

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

[Conventional technology]

Conventionally, as a method of forming a plating skin M on the surface of a copper strip,
Hot-dip plating is a widely used method in which a copper strip is immersed in pre-molten plating metal.

In continuous hot-dip galvanizing, which is a typical example of this type of plating method, the copper strip is heat-treated and surface-cleaned in a pretreatment furnace, and then immersed in a hot-dip zinc bath to form a plating skin Px. The plating adheres to the steel strip pulled out from the gas due to gas squeezing! Adjustment, galvanealing, etc. are performed on the surface v14.

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 galvanized steel, and as a result, problems with the quality of coated steel strips produced by conventional hot-dip galvanizing methods and the galvanized process itself have become apparent. Some of such problems are discussed below.

l) New assembly dross is often generated due to the elution of Fe from the surface of the steel strip during the plating bath and the oxidation of the plating metal, and as this must be pumped up and removed, it adheres to the copper strip. loss of plated metal occurs.

2) It is easy for impurities to be mixed into the plating bath, such as dross generated in the plating bath or debris from the bricks that make up the pot mixed into the bath, which adhere to the steel strip and deteriorate its appearance. .

3) The trace elements in the plating metal ingots that are put into the bath, the components that adhere to the copper strip, and the components that are discharged outside the bath as by-products such as dross are different, so the metal contains the necessary elements for the target penetration. It is difficult to adjust and control the composition of the soaking bath.

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) Work that involves high-temperature and large-volume work such as discharging bottom dross that accumulates at the bottom of the column, discharging top dross that accumulates on the bath surface, initial threading of steel strip into the bath, and maintenance of rolls in the plating bath. Working near a soaking 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 kinds of dissimilar plating, it is necessary to perform operations such as pumping out a bath, which is a common practice, or preparing a pot in which dissimilar plating metals are melted and moving the pot.

8) When double-sided plated material and single-sided plated material are buried in a single facility, it is necessary to change the plating equipment for the pot.9 In addition to the burden on the equipment, it takes a lot of time and effort to switch. Is required.

As described above, conventional hot-dip plating methods have various time periods.

In contrast to such conventional hot-dip plating methods, the present inventors have devised a new plating method that can overcome the above-mentioned problems.

In this method, as shown in Fig. 1, the metal plate (1), which is heated to a temperature higher than the melting point of the plated metal (1) and the metal plated with K1 (2), is brought into full contact with the metal plate (2) to melt them. By continuously supplying (2) to the metal plate (1), the molten plating metal (3) is continuously deposited as a plating film (4) on the surface of the moving metal plate. In addition, in order to ensure bath melting of the plated metal material (2) in this method, the K plated metal material (2) is preheated by a preheating device (5) as shown in Fig. 2. I can do it.

In this plating method, a plating metal material of the same phase is fed in the direction of the steel strip, and the sensible heat of the steel strip melts it on the surface of the copper strip by the plating area weight, and this bath molten metal is plated. Since it is applied as a metal and does not require a molten metal bath at all, the conventional problems associated with the use of plating baths can be solved at once.Moreover, the feeding speed of the solid plated metal material can be controlled. The amount of plating deposited can also be controlled with high precision.

[Problem 21 to be solved by the invention] In the above plating method, the plated metal material (2) is supplied between the metal plates at a constant speed by a constant speed motor. A slight variation in the feed rate has a very large effect on the amount of plating deposited. For example, when the thickness of the plated metal material (2) is 80 m+ and the plated metal plate (steel strip) speed is 2 nL/see, a fluctuation of only 0.1 9 ec in the plated metal material supply rate will cause the plated N
A variation of 4 μm in volume is assumed for each cow. Furthermore, such variations in the amount of plating are also caused by vibrations of the metal plate.

In actual operation, some variation in the plating metal supply rate and vibration of the metal plate to be plated are unavoidable, resulting in the formation of a patchy desert with non-uniform coating weight.

In view of these problems, the present invention aims to provide a method that allows continuous plating while preventing variations in the amount of plating deposited.

[Means to solve the problem]

For this reason, the present invention involves melting a plated metal material by bringing it into contact with a moving metal plate heated to a temperature higher than the melting point of the plated metal, and continuously supplying the plated metal material to the metal plate. From K, the molten plating metal is continuously applied as a plating film to the surface of a moving metal plate, and when continuously plating the metal plate, the plated metal material is always subjected to a constant reaction force from the metal plate. It is designed so that it is fed while being pressed against the copper strip.

The present invention will be explained in detail below.

In the above plating method on which the present invention is based, as shown in FIG. 1, a molten layer of plating metal (3) exists between the plating metal material (2) and the metal plate to be plated (1), In order to stably obtain the thickness of the plating film (4), it is necessary to maintain the molten layer (3) at a constant and appropriate thickness. However, the third
As shown in Figures B) and N), the molten layer (3) is formed due to fluctuations in the supply rate of the plated metal material (2), vibrations of the metal plate (1), etc.
The thickness of the plated film (4) varies, resulting in variations in the thickness of the plating film (4).

Therefore, in the present invention, as shown in FIG. 3), the metal material (2) with the dams is fed while being pressed against the metal plate (1) so as to always receive a constant reaction force from the metal plate. In this case, the solid phase of the plated metal material (2) is in almost metallic contact (human part in the figure) with the surface of the metal plate (1).

Figure 4 shows the relationship between the reaction force f applied to the plated metal material (2) and the amount of plating.There is a certain relationship between the reaction force and the amount of plating, so this reaction force is constant. A constant amount of plating can be obtained by supplying the plating metal material so that the amount of plating becomes constant. However, if the reaction force is excessively increased, it may cause flaws in the metal plate, and care must be taken to prevent such flaws from occurring.

In addition, in the present invention, adjustment of the plating adhesion amount is performed using the metal plate (1).
This is done by heating temperature etc.

In addition, the thickening film formed in the above manner may still have some unevenness in the amount of adhesion, so in order to equalize this unevenness, a surface conditioning device (6) as shown in @
(by) homogenization processing can be performed. As this surface conditioning device, for example, an ultrasonic vibration type device (so-called ultrasonic iron) having an ultrasonic vibrator is used, and the vibrating plate is lightly pressed against the plating surface to apply ultrasonic vibration to the plating film. By doing so, the thickness of the plating metal film is made uniform.

In addition, in order to prevent uneven plating adhesion due to vibration of the copper strip, as shown in FIG. 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 appropriate means such as an air action method or an electromagnetic force method.

Furthermore, in the present invention, it is also possible to run the copper strip (1) in a direction other than the horizontal direction; for example, it can be run in a vertical direction. In the case of this vertical line, the running direction may be either up or down. Further, in the method of the present invention, either one-sided plating or single-sided plating can be performed.

〔Example〕

Figure 7 shows an embodiment in which the present invention is applied to hot-dip galvanizing of copper strips, (8) is a tI4I4 thermal heating device, 5) a preheating device for plating metal materials, and (6) a plating device. Film surface adjustment device (V4) is a feeding roller that pinches both sides of the plated metal material.

Each plated metal material t2+ (zinc plate) is bitten by the feed roller (9) by the charging device a1, and is fed (moved) in the direction of the copper strip (1) by the feed roller (9).

In this example, the pinch roll (9) of the plated metal material (2) is
) K Torque detector C11l is installed to detect plated metal material (2J
(1) When pressing against the emperor, force is used as torque to the needle side, and this meter value is fed back to send 90-ra (9
), and the pushing force is controlled to keep the reaction force constant at Vζ.

According to such a method, for example, a steel strip (thickness 0.8 cm,
#A1220 earthquake) is run at a line speed of 120''/min to perform galvanizing of 4 of 7 m'', the variation in coating weight can be suppressed to within ft5%.

〔Effect of the invention〕

According to the present invention described above, the sensible heat of the metal plate passing through the solid plated metal material melts the plating area on the metal plate surface, and this is rolled to adhere to the metal plate as a plating film. , it is possible to continuously form a plating film with molten metal on a metal plate without the need for a molten metal bath, and it is possible to solve the conventional problems caused by the use of a molten metal bath. By controlling the feeding speed of the plated metal material, it is possible to control the amount of plating deposited on the striped oval box. In addition, the plated skin J[e
It can be formed uniformly without changing the amount of adhesion.

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams schematically showing the principle of the plating method that is the basis of the present invention. FIGS. 3B) and 3B are explanatory diagrams showing the formation of a molten layer due to melting of the plated metal material. Diagram M4 shows the relationship between the reaction force that a plated metal material receives from a metal plate and the amount of plating deposited. FIG. 5 is an explanatory diagram showing the case where the surface conditioning device 1 is provided in the method of the present invention, and FIG. M6 is an explanatory diagram showing the case where a pinch roll is provided on the upstream side. FIG. 7 is an explanatory diagram showing one implementation situation of the present invention. In the figure, (l) is a steel strip, (2) a fitted metal material, (
3) is the molten layer, (4) is the fitted film, (9) is the pinch roll, (1 (l is the supply pivot device, and 1) is the torque detector. l 1 Figure 111'. Figure 3 (a)
(b) Fig. 4 Reaction force f (kg) Fig. 5 6 Fig.

Claims (1)

[Claims] By bringing the plating metal material into contact with a moving metal plate that is heated to a temperature higher than the melting point of the plating metal, it is melted, and by continuously supplying the plating metal material to the metal plate. Molten plating metal is continuously applied as a plating film to the surface of a moving metal plate, so that the plated metal material always receives a constant reaction force from the metal plate when continuously plating the metal plate. A continuous plating method for a metal plate, characterized in that the metal plate is supplied while being pressed against the metal plate.