JPH01180954A - Hot dip metal coating device - Google Patents

Abstract

PURPOSE:To reduce the size of a device and to deal with production of diversified kinds in smaller lots by providing a direction changing roll to the lower part on the outside of a hot dip metal coating chamber to change the progressing direction of a steel strip perpendicularly upward from a horizontal direction. CONSTITUTION:The direction changing roll 54 is provided in the lower part on the outside of the hot dip metal coating chamber 52a. The progressing direction of the steel strip 15 from a heat treatment furnace is changed perpendicularly upward from the horizontal direction and the strip is introduced through a through-hole 55 in the bottom of the chamber 52 into the plating chamber 52a. On the other hand, twin rolls 56a, 56b to pinch the strip 15 is disposed in the plating chamber 52a and a molten metal 58 is supplied to form a molten metal pool 59 between the twin rolls 56a, 56b and the strip 15. The surface of the steel strip 15 is thereby subjected to uniform hot dip metal coating.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement in an apparatus for applying hot-dip metal plating such as hot-dip galvanizing, and in particular to the miniaturization of the apparatus. The present invention relates to the achieved molten metal plating equipment.

[Conventional technology] Hot-dip metal plating has been widely practiced for a long time, but as the products of hot-dip metal plating become more diversified, there is a growing demand for equipment that can handle small lots and a wide variety of products. It's here. A conventional hot-dip metal plating apparatus will be described below with reference to the drawings.

FIG. 2 is a schematic explanatory diagram showing an example of a conventional hot-dip galvanizing apparatus. In Figure 2, a steel strip a is heated in an annealing furnace and then guided by deflector rolls C and zinc rolls d into a large immersion tank e containing molten zinc Zn, where it is impregnated with molten zinc. It is done. The hot-dip-plated steel strip a is guided upward, and after adjusting the plating weight with a wiper g provided just above the bath surface of the immersion tank e, it is taken off via a deflector roll f.

As a plating device other than the above, for example,
A device such as that disclosed in Japanese Patent No. 345 is also known. 3 and 4 (cross-sectional view taken along the line IV-IV in FIG. 3) are diagrams for explaining the configuration of the apparatus, and the steel strip 15, which is the material to be plated, is ideal for hot-dip galvanizing. After being treated in a heat treatment furnace to achieve the desired conditions (temperature and surface activity), it enters the plating apparatus 1 through a connecting part 13, passes through a carrier roll 14, and then is transferred to a plating roll 2 provided as necessary.
a molten metal flow (or injection) device 3.3' on the upper side of the
The molten zinc flows down (or is injected) from 3" and adheres to the steel strip 15. At this time, the amount of molten zinc coating is adjusted by, for example, the squeezing roll 5 or the jet gas from the protective air scum injection device 4. Then, it passes through a squeeze and seal roll 6 provided at the outlet of the plating device 1, and if necessary, the amount of plating adhesion is further adjusted by a fluid injection device 7 (see lines 21 to 37 of column 3 of the official gazette). 10 in the diagram
．． 12 is an electromagnetic pump, 11 is a molten metal supply pot, 16
17 shows a liquid level gauge, and 17 shows a new plating metal supply device.

Furthermore, as another plating device, for example, the
There is a technique disclosed in Japanese Patent No. 668. As shown in FIG. 5, this apparatus has a configuration for applying molten metal plating to a thick coil moving horizontally, and its details are as follows.

That is, a molten metal injection nozzle 33 is provided in the plating chamber 26 to face at least one or both sides of the material to be plated 31, and the molten metal 38 is supplied from a molten metal container 37 by an electromagnetic pump or a metal pump 36. It is sent from the pipe 34 to the nozzle 33, and is sprayed from the nozzle 33 toward both sides of the material to be plated 310. 35 is a flow rate control device.

The surplus of the molten metal sprayed onto the material to be plated 31 is
It flows down a passage 40 provided at the bottom of the plating chamber 26 and is collected in a metal container 37 . Impurities such as residual flux and dross generated in the plating process are separated and removed from the molten metal 38 by an impurity removal device 39, and then transferred to the molten metal container 3.
The molten metal No. 7 is circulated and supplied in a clean state (see lines 7 to 21 of column 2 of the official gazette). In addition, 24 in the figure is a preheating chamber, 28
29 is a curtain chamber, 29 is a plating squeeze roll, 30 is an inert gas inlet, 41 is a plating metal supply device, and 44 is a transfer roll.

[Problems to be Solved by the Invention] As described above, hot-dip metal plating apparatuses having various configurations and mechanisms have been developed, but all of them have had various problems as shown below.

That is, in the conventional apparatus shown in Fig. 2, a large amount of metal (usually 100 to 120 tons) must be melted in the immersion tank e, which requires a large amount of time and heat energy when changing the bath composition. However, it is difficult to meet the demands of small-lot production and multi-product production. There is also the problem that a large amount of dross is generated due to oxidation of the molten metal in the immersion tank and reaction with the steel strip, etc., which deteriorates the surface quality of the plating.

Furthermore, in the conventional apparatus shown in FIGS. 3 and 4, the steel strip 150 is guided by a carrier roll 14 provided in the plating apparatus 1, but in order to prevent plastic deformation of the steel strip 15, the carrier roll 14 from 500
Since the plating apparatus 1 must have a large diameter of 600 mm or more, the size of the entire plating apparatus 1 is unavoidable, making it difficult to handle small lots and a wide variety of products. Moreover, like the conventional device shown in FIG. 2, product defects due to dross are unavoidable. Furthermore, according to the above-mentioned public notice, "excess molten metal flows down to both sides along the plating roll 2, and the protective atmosphere gas injected from the protective atmosphere gas injection device 8 protects the steel strip 15 before plating." However, as is clear from FIG. 4, the width of the carrier roll 14 provided directly below the plating roll 2 is equal to the width of the steel strip 15. Protection: Molten metal blown away by surrounding gas adheres to the surface of the carrier roll 14, causing scratches or poor meshing when the steel strip 15 is changed to a wider width. There was also.

Is that a scale?This technology uses a 10°12 electromagnetic pump to circulate and supply molten metal, so it doesn't generate much power, and requires a combination of multiple pumps, which poses problems in terms of energy costs and equipment costs. be.

Next, with the conventional equipment shown in Fig. 5, it is possible to downsize the plating equipment, making it easier to handle small lots and a wide variety of products, and also to prevent dross by using the impurity removal device 39. Since the thick coil is configured to advance horizontally, the amount of plating deposited tends to be uneven between both sides (the thickness is different between the top and bottom surfaces) or even in the width direction of the strip. There was a problem in that it was difficult to achieve uniformity in the amount of plating deposited.

The present invention was made in order to solve the problems of the conventional apparatus described above, and its main purpose is to provide a plating apparatus that can be miniaturized and can handle small lots and a wide variety of products. The object of the present invention is to provide a plating apparatus that can achieve uniformity of the amount of plating deposited.

[Means for Solving the Problems] The apparatus of the present invention that achieves the above object is equipped with a direction change roll that changes the traveling direction of the steel strip from a horizontal direction to an upward vertical direction, and is installed in a molten metal plating room or in a non-oxidizing atmosphere. In a molten metal plating apparatus configured to apply molten metal plating to the steel strip under controlled conditions, the apparatus is miniaturized by providing the direction changing roll below the outside of the molten metal plating chamber. It is something.

Further, in the above configuration, "twin rolls are arranged in the molten metal plating chamber so as to sandwich the steel strip, and molten metal is supplied between the twin rolls and the strip to form a puddle, and the molten metal is uniformly spread over the surface of the steel strip. By adding a configuration such as ``applying hot-dip metal plating,'' the objective of making the amount of plating coating uniform is also achieved.

[Effect] The configuration and effects of the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic explanatory diagram showing an embodiment of a plating apparatus according to the present invention, and FIG. 6 is a cross-sectional view taken along the line Vl--Vl in FIG. The overall configuration of the equipment in which this plating apparatus 1 is installed is the same as that of ordinary continuous hot-dip galvanizing equipment for steel strips, and for example, as shown in FIG. 7, it is installed connected to a heat treatment furnace. . In Fig. 7, A is a coil, B is a shearing machine, C is a welding machine, D is a louver, F is an alloying processing furnace, G is a heating tower, H is a skin bath, ■ is a tension leveler,
J indicates a chemical treatment device, L indicates an oiler, and M indicates a coiler.

In the plating apparatus 1 of the present invention, a direction changing roll 54 is provided outside and below a molten metal plating chamber 52a (hereinafter referred to as a plating chamber) formed by a chamber 52. The plating chamber 52a has a lock system 53a.
, 53b, and is controlled to provide a non-oxidizing atmosphere that is optimal for molten metal plating.

In the plating apparatus 1, the steel strip 15 as a material to be plated is heat-treated in a heat treatment furnace E (see FIG. 7) so as to provide the optimum conditions for hot-dip plating, and then the steel strip 15 is heated in the direction of movement from the heat treatment furnace or as described above. The direction change roll 54 converts the horizontal direction to the vertical direction upward. A through hole 55 is formed at the bottom of the chamber 52, and the steel strip 15 turned vertically upward by the turning roll 53 is guided into the plating chamber 52a through the through hole 55.

On the other hand, twin rolls 56a and 56b are arranged in the plating chamber 52a so as to sandwich the steel strip 15, and the molten metal 5 is placed between the twin rolls 56a and 56b and the strip 15.
By supplying 8, an easy pool 59 is formed. This molten metal 58 is transferred from the molten metal container 61 to the nozzles 63a, 63 by an impeller ceramic pump 62.
b, from the nozzles 63a, 63b to the twin rolls 56.
a, 56b and the strip 150. Further, the molten metal container 61 is separately supplied with molten metal 58 from the supply line 50 in accordance with the consumption amount of the molten metal 58. The nozzles 63a and 63b are provided with a mechanism that allows the nozzle width to be varied in accordance with the width of the steel strip 15. The supply flow rate of the molten metal 58 to the sump 59 depends on the line speed,
Adjusted according to board width, target plating thickness, etc.

The plating apparatus is equipped with a sensor 65 as shown in FIG. 6 from the viewpoint of minimizing the amount of surplus metal in the molten metal 58 supplied between the twin rolls 63a and 63b. A control device 66, a double-acting cylinder 67, a cytotom 68, etc. may be provided, and this device detects the edge portion 70 of the steel strip 15 with the sensor 65 and returns the signal via the control device 66. The position of the side dam 68 is changed by sending the water to the moving cylinder 67, and the position of the side dam 68 is changed.
9 or adjust to the optimum capacity corresponding to the width of the steel strip 15. The gap between the site dam 68 and the strip 15 is preferably about 10 mm in order to prevent wear of the site dam 68 while controlling leakage of the molten metal 58 on the sides. In addition, in this illustrated example, gas jet nozzles 71a and 71b are provided below the twin rolls 63a and 63b to prevent the molten metal 58 flowing out from the gap from adhering to the strip 15 before the clinching process. By spouting an inert gas (non-oxidizing gas) similar to the atmospheric gas in the plating chamber 52a through the et nozzles 71a and 71b, excess molten metal 58 is removed into the molten metal pit 75 at the bottom of the plating chamber 52a. carrying it to.

The surplus molten metal 58 carried into the molten metal pit 75 is
It is sent to the molten metal container 61 and used for circulation. Since impurities such as dross gradually increase in the molten metal 58 in the molten metal pit 75 and the molten metal container 61, the plating apparatus 1 is immersed in the molten metal container 61 to remove impurities. A device 77 is provided which keeps the molten metal 58 sent to the pool 59 clean by successively removing impurities. This impurity removal device 77 is configured by, for example, a ceramic filter. Additionally, a molten metal supply system (pump 62, container 61, etc.), chamber 52° nozzles 63a, 63b, and twin rolls 56a.

Needless to say, 56b has a heating/insulating structure.

In the plating apparatus 1 of the present invention, the steel strip 15 led into the plating chamber 52a passes through a pool 59 formed at the top of the twin rolls 63a, 63b, so that molten metal is adhered to the surface, and then the steel strip 15 is introduced into the plating chamber 52a. Wiping nozzle 79a.

Gas injection pressure and injection angle from 79b, nozzle 63a,
The amount of plating deposited is controlled by adjusting the distance between 63b and the strip 15, and the material becomes a molten metal plating material 15a, which is sent to the upper part of the plating apparatus 1 through the upper through hole 55a and subjected to subsequent processing. . In addition, the waste wiping nozzle 79a.

Instead of 79b, a wiping roll may be installed to control the amount of plating deposited. Also, the gas wiping nozzles 79a, 79b and the gas jet nozzle 71
From the viewpoint of preventing a drop in the temperature of the steel strip 15, the atmospheric gas supplied from a and 71b should be appropriately heated and supplied.

The plating apparatus 1 of the present invention is configured as described above, or in other words, the plating apparatus 1 is miniaturized by providing the direction changing roll 54 outside and below the muffing chamber 52a.
This makes it possible to manufacture small lots and a wide variety of plated products. Furthermore, since the puddle 59 is formed by the twin rolls 56a and 56b and the steel strip 15 is passed through the puddle 59, the amount of plating deposited on the steel strip 15 in the width direction is also uniform. It is also possible to apply molten metal plating to only one side of the steel strip 15 by supplying molten metal 58 from only one of the nozzles 63a, 63b.

FIG. 8 is a schematic explanatory diagram showing another embodiment of the present invention.

The basic configuration of this device 1a is similar to that shown in FIG. 1, and corresponding parts are given the same reference numerals to avoid redundant explanation. In this example,
Twin rolls 56a.

56b are replaced by electromagnetic coils 80a, 80b whose electromagnetic force causes a pool 59 to form in the area of passage of the steel strip 15. In this embodiment, the impeller ceramic pump 62 is provided immersed in the molten metal 58.
Impurities such as dross in the molten metal 58 that is circulated and supplied by the pump 62 are removed by an impurity removal device 77a provided in the middle of the pipe line 81.

Even with the device having the configuration shown in FIG. 8, the same effects as the device shown in FIG. 1 can be achieved.

Hereinafter, the present invention will be explained in more detail with reference to examples, and the following examples are not intended to limit the present invention, but
Any design changes for the purposes described below are included within the technical scope of the present invention. In addition, in the following examples, explanation will be given by taking up hot-dip zinc alloy plating as a representative example of hot-dip metal plating, or the apparatus of the present invention is not limited to the case of applying hot-dip galvanizing, but can also be applied to cases of applying other hot-dip metal plating. Of course.

[Example] A steel strip 15 pretreated in a heat treatment furnace as shown in FIG. 7 was guided through a direction change roll 54 into a plating chamber 52a of a plating apparatus 1 shown in FIG. At this time, the temperature of the steel strip 15 was about 480° C., and the inside of the plating chamber 52a was controlled to have an atmosphere of N2+H2 atmosphere. Further, the line speed of the steel strip 15 was set at 10 m/min.

The molten zinc alloy in the molten metal container 61 is kept at a temperature of approximately 485°C, and the molten zinc alloy is supplied between the twin rolls 56a and 56b by the impeller pump 62, and the molten zinc alloy is supplied to the pool 5.
9 was formed. The twin rolls 56a and 56b are 200 mm in diameter and equipped with a heating mechanism, and the temperature is approximately 460°C.
It was soaked to heat. The twin rolls 56a and 56b were subjected to a ceramic surface treatment in order to maintain good wettability to the molten zinc alloy.

The steel strip 15 with the molten zinc alloy adhered between the twin rolls 56a and 56b was made into a double-sided plated steel strip material of 60 g/m2 by controlling the plating thickness by backward swiving.

When we investigated the plating properties of the obtained plated steel strip material, such as plating adhesion, corrosion resistance, and workability, we found that:
I did not check to see if both were in good condition. Further, no dross adhesion was observed on the surface of the plating material, and good surface quality was obtained. Furthermore, when the uniformity of the coating weight was investigated, it was confirmed that the steel strip 15 was uniform in both the width direction and the length direction. Furthermore, the plating apparatus of the present invention allows the capacity of the molten metal container 61 to be as small as about 15 tons, compared to the conventional apparatus.
Considering that it had a capacity of ~120 tons, we were able to confirm that it was extremely compact and had a configuration that could be used to manufacture a wide variety of plated products in small lots.

[Effects of the Invention] As described above, according to the present invention, by configuring the direction change roll to be provided outside and below the plating chamber, the plating apparatus can be downsized, and it is possible to use small lots and a wide variety of products. has become easier to deal with. Furthermore, in addition to this configuration, by adopting a configuration in which a pool of hot water is formed and the strip is passed through the pool, it has become possible to achieve a uniform coating amount of plating.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional explanatory diagram showing one embodiment of a plating apparatus according to the present invention, FIGS. 2 to 5 are schematic explanatory diagrams showing a conventional plating apparatus, and FIG. 6 is a line Vl-Vl in FIG. 1. Cross-sectional view,
FIG. 7 is a schematic explanatory diagram showing the overall configuration of equipment in which the plating apparatus of the present invention is installed, and FIG. 8 is a schematic vertical cross-sectional explanatory diagram showing another embodiment of the present invention.

Claims (2)

[Claims] (1) It is equipped with a direction change roll that changes the traveling direction of the steel strip from a horizontal direction to an upward vertical direction, and is configured so that the steel strip is subjected to molten metal plating while the molten metal plating chamber is controlled to have a non-oxidizing atmosphere. A molten metal plating apparatus characterized in that the direction change roll is provided below outside the molten metal plating chamber. (2) In the molten metal plating chamber, twin rolls are arranged to sandwich the steel strip, and molten metal is supplied between the twin rolls and the strip to form a pool of molten metal, resulting in uniform molten metal plating on the surface of the steel strip. A claim (1) structured to provide
) The hot-dip metal plating equipment described in ).