JPH0718394A - Zinc base metal charging method for galvanizing - Google Patents

Abstract

PURPOSE:To stabilize the flow state of a galvanizing bath by supporting the lower part of a zinc base metal with a supporting plate and maintaining the volume of the part of the base metal to be immersed into the bath nearly constant at the time of charging the zinc base metal into the galvanizing bath. CONSTITUTION:The zinc base metal 6 is hung by holding pawls 7 and the front end of the base metal is immersed into the galvanizing bath 4 and is melted to replenish the bath with a required amt. of the base metal during plating operation. The holding pawls 7 are lowered according to melting of the zinc base metal 6. The supporting plate 8 is put under the zinc base metal 6 and the holding pawls 7 are opened to place the zinc base metal 6 on the supporting plate 8 and is melted in the state when the melting progresses from (a) to (c) and the margin for lowering of the holding pawls 7 reaches the threshold (d). The zinc base metal 6 is melted without dropping of the residual lump in the hanging part of the zinc base metal by disposition of such supporting plate 8 and, therefore, the fluctuation on and in the bath is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for introducing zinc metal in hot dip galvanizing, and particularly to attain a stable fluidized state in a zinc bath.

[0002]

2. Description of the Related Art The flow of the prior art will be described with reference to FIG. In FIG. 3A, a zinc base metal (ingot) 6 is held by an ingot holding claw 7 and placed in a plating bath. Figure 3 (b)
Is the height h at which the ingot 6 has melted,
I put ingot 6 in. The speed of inserting the ingot 6 can be increased or decreased. FIG. 3C shows that the ingot 6 is melted and the holding allowance of the holding claw 7 reaches the limit. In FIG. 3D, the holding claw 7 is opened and the ingot residual mass is dropped into the plating bath 4. At this time, fluctuations occur in the bath surface and in the bath, and scum in the snout or dross in the bath adheres to the steel plate, causing a trouble on the plating surface appearance.

There is also a conventional method in which an auxiliary pot 9 is provided in the plating bath 4 as shown in FIG. In FIG. 4A, the holding claw 7 is opened and the ingot 6 is dropped into the auxiliary pot 9. Thereafter, the ingot gradually melts as shown in FIG. 4 (b) → (c) → (d). Even in this method, as shown in FIG.
During the operation of (a), fluctuations occur in and on the bath surface. Therefore, the scum inside the snout and the dross in the bath adhere to the steel plate, which causes a trouble on the plating surface appearance.

[0004]

DISCLOSURE OF THE INVENTION The present invention proposes a zinc base metal injection method for hot dip galvanization that does not cause fluctuations in the plating bath surface and the plating bath.

[0005]

The gist of the present invention is as follows. When the zinc ingot is put into the hot dip galvanizing bath, the lower part of the zinc ingot is held by the ingot support plate, and the volume of the zinc ingot immersed in the zinc bath is made almost constant. How to insert zinc metal in hot dip galvanizing.

[0006]

In the present invention, since the remaining ingot of the plating bath is held by the support plate, the ingot does not drop into the plating bath even if the ingot holding claw is released. Therefore, the fluctuation of the plating bath does not occur.

[0007]

1 is a diagram showing an embodiment according to the present invention.
Steel plate 1 has a thickness of 0.23 to 3.2 mm and a width of 500 to 1829.
It is a cold rolled steel sheet or a hot rolled steel sheet of about mm. The annealed steel sheet 1 changes its traveling direction by a turndown roll 2, passes through a snout 3, enters a zinc bath 4 and is dipped and plated. The inside of the snout 3 is in a reducing atmosphere. Zinc bath 4
It is a bath in which metals such as Zn, Al, Pb, and Sb at about 430 to 475 ° C. are melted.

The zinc feeding device 5 is a device for replenishing zinc or the like that adheres to the steel plate 1 and decreases. The supply of bath components is performed by charging the ingot 6 into the bath. When the zinc feeding device 5 is horizontal, the ingot 6 is inserted, the ingot holding claw 7 is inserted into the recess of the ingot, and the ingot is grabbed. Next, the zinc feeding device 5 is tilted and the holding claw 7 is moved to put the ingot 6 in the plating bath 4. When the ingot 6 is melted and the remaining lump of the holding portion is dropped, the ingot support plate 8 is placed near the bath surface (in the bath) below the remaining lump.

FIG. 2 is a flow chart at the time of loading the ingot according to the present invention. In FIG. 2A, an ingot 6 is grasped by an ingot holding claw 7, put in a plating bath 4, and melted.
In FIG. 2B, the ingot 6 is placed in the plating bath 4 at a height h at which the ingot 6 has melted. The speed of inserting the ingot 6 can be increased or decreased. In FIG. 2C, the ingot 6 is melted and the ingot support plate 8 is also placed in the bath at the same time when the lowering margin of the holding claw 7 reaches its limit.

In FIG. 2D, the ingot support plate 8 is put under the ingot 6, the ingot holding claw 7 is opened, and the ingot 6 is placed on the support plate 8. That is, since the remaining ingot mass is placed on the support plate 8 without being dropped into the zinc bath 4, the bath surface and the interior of the bath do not change. Therefore, there is an effect of preventing zinc powder (scum) adhering to the inner wall of the snout 3 which tends to occur when the bath surface changes, from adhering to the steel plate, and dross floating in the bath adhering to the steel plate.

[0011]

According to the present invention, it is possible to obtain a stable fluidized state without dropping the ingot residual mass into the plating bath and disturbing the fluidized state in the plating bath.
By stabilizing the plating bath, scum in the snout does not adhere to the steel sheet and disturbs the plating surface appearance.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the present invention.

2 (a) to 2 (d) are explanatory views of the operation of the present invention.

3A to 3D are explanatory views of a conventional example.

4A to 4D are explanatory views of another conventional example.

Claims (1)

[Claims] 1. When the zinc ingot is put into the hot dip galvanizing bath, the lower part of the zinc ingot is held by an ingot support plate so that the volume of the zinc ingot immersed in the zinc bath is almost constant. A method of applying a zinc metal for hot dip galvanizing, which is characterized in that