JPS61235550A - Method for controlling plating deposition in meniscus coating method - Google Patents

Abstract

PURPOSE:To adjust freely the plating metal deposition on a metallic strip in the stage of subjecting the metallic strip to metal hot dipping by a meniscus coating method by providing a gate consisting of plural divided bodies to a nozzle aperture for a plating metal and closing partially the aperture thereby controlling the passage rate of the molten metal. CONSTITUTION:The gate 3 consisting of the plural divided bodies 4 is provided to the aperture 2 of a nozzle 1 of a molten metal vessel 8 plating and the bodies 4 are made vertically slidable by means of an actuating rod 6 fixed to the upper part of the gate. The metallic strip 13 is moved upward by a deflector roll 12 in front of the aperture 2 of the nozzle 1 and is plated by the molten metal 7 for plating sucked out of the aperture 2 of the nozzle 1. Part of the bodies 4 are partially lowered by the rod 6 to close partially the space in the part of the gate 3, by which the passage rate of the molten metal for plating through the nozzle is controlled and the plating metal deposition on the metallic strip 13 is freely adjusted.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention uses a plating nozzle having a protruding weir inside the closed part to narrow the gap between the openings, to plate a metal strip by a meniscus coating method. The present invention relates to a method for controlling the amount of plating deposited by adjusting the amount of molten metal sucked out from the plating nozzle.

(Prior art) As a method of applying hot-dip plating to a metal strip, a plating finishing nozzle is provided in a molten metal bath, and the metal strip is run while being brought very close to the molten metal tank, thereby plating the metal strip and the nozzle opening. There is a method in which the molten metal is sucked out by the wet adhesion with the bath and the metal strip is plated by 7 varnish coating.

When performing hot-dip plating using this meniscus coating, the amount of plating deposited is mainly determined by the running speed of the metal strip, the distance between the metal strip and the nozzle opening, and the amount of molten metal sucked out. This method has been used because it is easy to maintain a constant distance between the metal strip and the nozzle opening and to adjust the amount of molten metal sucked out.

(Problem to be solved by the invention) However, when controlling the final coating amount by adjusting the distance between the metal strip and the nozzle opening, the coating amount depends on the distance between the metal strip and the nozzle opening. As shown in FIG. 4, there is a tendency for the value to change rapidly, but not to change much before and after that value. Therefore, for stability of control, the distance between the metal strip and the nozzle opening must be set in a range where the amount of plating does not vary greatly, and it may not be possible to set the amount of plating to the desired amount.

On the other hand, when controlling the amount of plating deposited by the amount of molten metal sucked out, conventionally a weir 3 is provided protruding inside the opening 2 of the nozzle 1 as shown in FIG. This was done by narrowing the . Let's do it here! 3 is provided protruding inside the opening 2 because it is necessary to leave a certain amount of clearance at the tip of the opening 2 in order to form a 7 varnish of molten metal. However, since the drain 3 was fixed and protruded from the nozzle 1, it was necessary to temporarily stop plating and replace the nozzle 1 in order to adjust the amount sucked out.

Also, let's put it inside this opening 2! In the case of the method in which the amount of molten metal sucked out is adjusted by installing a protruding nozzle 3, if the gap is narrowed by the weir 3, the nozzle is likely to become clogged, and the molten metal may not be sucked out smoothly. .

(Means for Solving the Problems) The present invention provides a method for controlling the amount of plating that does not cause the above-mentioned problems when the amount of plating is controlled by the amount of molten metal sucked out. The protruding opening part is partially closed to control the amount of molten metal sucked out. That is, the present invention partially closes the opening while maintaining a constant gap in the protruding part of the weir inside the closing part of the plating nozzle to narrow the area through which molten metal can pass. This controls the amount of water that is sucked out.

・In the present invention, the method of partially closing the opening is (1) The weir is composed of a plurality of divided bodies that are individually slidable in the direction of opening, and some of them are closed at equal intervals in the direction of opening. (2) A method of lowering the plate in the flow direction of the molten metal by arranging rotating shafts extending in the weir direction at equal intervals, fixing the plate to the ring, and rotating the rotating shaft. There are ways to change the angle of the

Although the present invention alone may be used to control the amount of plating deposited, it is also possible to use the present invention together with adjustment of the traveling speed of the metal body and the distance between the metal body and the nozzle opening.

The present invention will be explained below with reference to Examples.

(Example) Figure 1 shows /'Xnil 1 used in the present invention,
In the tl&i diagram, (a) is a perspective view, (b) is a front view, and (c)
shows a cross-sectional view at ^-^ of (b). Cough 3
is provided protruding inside the frontage part 2 as in the case of the conventional nozzle 1, but the weir 3 is composed of a plurality of divided bodies 4,
Each of them is held so as to slide against the wall 5. An operating rod 6 is fixed above each divided body 4 so that each divided body 4 can be slid in the opening direction.

As described above, the weir 3 is constructed from a plurality of divided bodies 4, and #
As shown in Figure 1, if parts of the divided body 4 are lowered at equal intervals using the actuating rod 6, the gap in the weir 3 is partially closed, so the area through which molten metal can pass becomes smaller. , the amount sucked out will be smaller.

Note that even if the gap in the weir 3 of the opening 2 is partially filled with the dividing body 4, the flow of molten metal will be uniform by the time it reaches the tip, so the plating in the width direction of the metal strip will be The adhesion amount distribution becomes constant. Also, when lowering the divided body 4, the operating rod 6
may be moved manually or automatically.

FIG. 2 shows an embodiment of a plating apparatus in which the actuating rod 6 is automatically moved and the nozzle 1 shown in FIG. 1 performs plating while controlling the coating amount.
Protruding from the lower side of the molten metal tank 8 of the plating tank 7,
The operating rod 6 of each divided body 4 constituting the box 13 is pivotally attached to one end of each lever 10 provided on the box 9. An air cylinder 11 is pivotally attached to the other end of each lever 1°, and each divided body 4 constituting the weir 3 is moved up and down by this air cylinder 11.

There is a deflector in front of the nozzle 1 protruding as described above.
A roll 12 is arranged and the deflector roll 12 changes the direction of the horizontally moving steel strip 13 upward so that the steel strip 13 approaches the tip of the nozzle 1. If the steel strip 13 is moved in such a state, the molten metal is sucked out from the opening 2 of the nozzle 1 by the copper strip, so that the steel strip 13
It is plated. Note that 14 is a plating bath supply device;
The inside of box 9 is made into an inert or reducing atmosphere.

Next, a case will be described in which hot-dip galvanizing is applied to a copper strip by controlling the amount of plating deposited using the plating apparatus shown in FIG. In this case, the nozzle body of the nozzle 1 is made of isotropic electrographite, and when the weir 3 is slid, the part that the weir 3 contacts is reinforced with ceramics made of aluminum titanate crystal, and the weir 3 is A structure made up of two divided bodies 4 was used. When preparing mackerel, set the gap between the weir 3 to 0.7I, the width of the opening 2 to 100mm, the temperature of molten zinc in the nozzle 1 to 480℃, and the distance between the opening 2 and the metal strip. to 0.8, and the running speed of the copper strip to 6.
0 m/sin, and during plating, the divided bodies 4 were partially lowered at equal intervals to partially close the gap in the plate 3 to adjust the amount of plating deposited. As a result, the amount of plating deposited could be controlled to 10 to 90 μm.

(Effects) As described above, the present invention does not narrow the gap between the thin and light parts, but controls the amount of plating by partially closing the gap while keeping the gap constant. There is no need to stop plating when changing the amount, and nozzle clogging does not occur.

[Brief explanation of the drawing]

FIG. 1 shows a plating nozzle used in the present invention, in which (a) is a perspective view, (b) is a front view, and (c) is a cross-sectional view taken along the line ^-^ of (b). FIG. 2 shows an embodiment of plating equipment for controlling the amount of plating deposited according to the present invention. Figure 3 shows a conventional plating nozzle.
A) is a front view, and (B) is a sectional view at B-8. FIG. 4 is a graph showing changes in the amount of plating deposited depending on the distance between the opening of the plating nozzle and the metal strip.

Claims (1)

[Claims] A plating nozzle having a protruding weir inside the opening that narrows the gap between the openings is provided in the molten metal tank, and the metal strip is run in close proximity to the nozzle to separate the metal strip and the nozzle opening. In a meniscus coating method in which a metal strip is plated by sucking out molten metal by the wet adhesion force with a plating bath, while maintaining a constant gap between the parts where the weirs protrude inside the closing part of the plating nozzle,
A method for controlling the amount of plating deposited in a meniscus coating method, which comprises partially closing an opening to narrow the area through which molten metal can pass, thereby controlling the amount of molten metal sucked out.