JPS60141391A - Working method of plate for discharging molten metal - Google Patents

Abstract

PURPOSE:To work quickly and uniformly a plate for discharging a molten metal by working the small hole or slit of said plate by a laser. CONSTITUTION:Laser light 1 is condensed to the focus 3 of a lens 2 and works a small hole or slit to a work 4. If the distance between the focus 3 and the surface of the work 4 is designated as focal depth H, the focal depth H is preferably 0-10mm. from the surface of the work 4. Tar or the like is impregnated in the work 4 (plate for discharging a molten metal) for the purpose of improving durability. Laser absorptive power is higher with the impregnated work than the non-impregnated work in the stage of laser working and therefore the small hole is efficiently opened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for processing a molten metal discharge plate that is attached to the bottom of a ladle or tundish when molten metal is cast.

When casting molten steel using the conventional continuous casting method, a molten metal discharge device consisting of a fixed plate and a sliding plate is attached to the nozzle at the bottom of the ladle or tundish containing the molten steel. By sliding the molten steel against the molten metal, the molten hook opens a passage hole and adjusts the flow rate of molten steel. In the above-mentioned molten metal discharge device, the molten steel passage hole is used for solidification of molten steel, AL, Ti,
Ca, Cr.

The metal ones such as I! Place Ar on the fixed plate or sliding plate to prevent blockage due to chemical separation.
It is common practice to supply inert gas such as

The non-Yδ gas can be supplied using a gas supply body made of a large porous surface, a gas supply body provided with several small holes with a diameter of 01 to 1.0I1 m, or a gas supply body provided with multiple slits. This is done by placing the body in front of the Qr stereotaxic position of the plate. When forming small holes or slits here, hard paper or vinyl wire is embedded in the clay at a predetermined negative position during molding, and the hard paper or vinyl wire is burned out during the firing process. Provide holes or slits,
After firing, it was drilled to create small holes or slits. However, when making small holes or slits using hard paper or vinyl wire, it is necessary to
However, there were disadvantages such as the gas supply being uneven due to non-uniformity in the diameter of each hole, and the work being labor-intensive. In addition, when machining using a drill, it is extremely difficult to process the object, and the work requires a lot of effort.
There were problems such as being expensive.

4. The invention was made in view of the above-mentioned real axis, and when forming small holes or slits directly in the gas mediator fitted to the plate or in the plate, the small holes or slits are formed by laser processing after molding and firing. This is a method for processing a plate for discharging molten metal, which is characterized by providing a slit.

According to the present invention, small holes or narrow slits with a diameter of about 0.2 to 10 mm can be processed quickly and uniformly. In addition, when drilling a hole with a laser, the hole is opened by melting and scattering, so the processed surface, that is, the inner surface of the hole and the periphery of the hole surface, are in a molten state. This improves the performance compared to the conventional one. Hereinafter, the laser-equipped tuna and acid melt FA discharge plate used in the present invention will be explained.

1 and 2 show a laser device used in the present invention. Reference numeral 1 indicates a laser beam, which is focused on a focal point 3 of a lens 2. FIG. There is a workpiece 4 at the focal point 3. The workpiece 4 is a plate of the present invention in which a small hole or slit is to be formed. The focal point 3 and the surface of the workpiece 4 have a focal depth I4. The depth of focus H is 0 to 1 from the surface of the workpiece 40
The hole diameter is preferably 0, and the farther the focal point 3 is from the workpiece 4, the larger the hole diameter becomes.

Moreover, if the diameter exceeds 10, it will take a long time to open the hole and the hole diameter will become large.

In addition, the workpiece 4 (molten metal IA discharge plate) is generally impregnated with tar to make sliding smoother, but it is better to perform laser processing after the tar is impregnated so that the tar stays healthy and evaporates. The scattering of the particles is promoted, making it efficient to open small holes.

The lens 2 is attached to a nozzle 5, and the nozzle 5 is provided with auxiliary gas flow holes 6 for scattering the lens and melt. N2 + 02 as auxiliary gas
r Air, etc., but N2. Air is preferable, flow is 30
~150t/rnin is preferred. This is 3017m
If it is less than r n, there will be little scattering of the melt and the pore size will be poor, while if it exceeds 150 t/rnin, the scattering will be too intense and the pore diameter will become large.

Furthermore, the average output of the laser beam used in the present invention is 20
(It is more than 1, and if it is less than this, the time for machining will be longer and it is not preferable. The maximum output is preferably 1 kW or more, and the frequency and pulse width are 50 to 1 kW.)
50 Hy, a pulse width of 3 to 10 seconds is ideal; outside this range, the temperature of the surface is not appropriate, it takes a long time to open the hole, and the IRI porosity becomes poor.

The focal length of lens 2 is preferably 5 to 15 inches, and if it is longer than 5 inches, the aperture of focal point 3 will be too large.
I miss the pore size. If the diameter exceeds 15 inches, there is a disadvantage that the density of the laser beam 1 is low and it takes a long time to open the hole.

It is preferable that the distance between the surface of the workpiece 4 and the nozzle 5 be close to 11, but if it is shortened, the molten particles will reach the nozzle 5 and the nozzle 5 will become clogged. 2 to 15 fights is preferred. Moreover, if the diameter exceeds 15, the scattering of the melt will be small and the porosity will be poor.

L/-sample mode, double mode, and multimode are next), but songle mode is preferable for opening small holes.

Figure 1 shows the case where the process is performed on the gas supply body or sliding surface that is inserted into the plate after processing, but when the small hole or slit is directly drilled from inside the plate circulation hole, the process is as shown in Figure 2. Molten metal outlet hole 7 of object (plate) 4
A prism 8 is inserted into the laser 1 using the prism 8.
The small hole 9 or slit 9 may be drilled by reflecting the light and changing the angle. Note that 1() is 11 in the gas equal pressure zone.
is the gas introduction hole.

Figures 3 to 6 show the plate for extracting the molten metal phase, and Figure 3 shows the gas supply body 12 being fixed to the plate 13.
The gas supply body 12 is usually fixed to the fixing plate 13 with mortar or the like.

In addition, as shown in FIG. 4, there is no gas pressure body 12, and a gas pressure equalization zone 10 is provided on the fixed plate 13, and a small hole is provided between the outlet of the groove 1 and the gas pressure distribution zone 10. 9 may be provided, or slits may be provided instead of the small holes as shown in FIG. FIG. 6 shows a sliding plate 14 with a gas inlet, 13 is an upper fixing plate, 15 is a lower fixing plate, and the sliding plate 14 has a gas introduction hole 1.
6, a gas pressure equalizing part 17 is provided at the tip thereof, and a plurality of small gas ejection holes 18 are provided. When the molten metal discharge port is closed with the sliding plate 14, a vortex is placed at the bottom of the molten metal outlet, and gas is blown out into the molten steel in the same way as the small hole 9.

Next, we will explain the practical aspects of the present invention (examples).

Example 1 A fired ring-shaped gas supply body made of crystalline alumina (thickness 15
external surface, average output 500W, frequency 1 (IOH
2,' EO2 laser with pulse width 5m5ec, lens extension distance #10 inch, depth of focus from processing surface)
5n+, the distance between the processed surface and the nozzle tip is 11115 m, and the pressure of 3K97cm2ON2 gas is 7 as the auxiliary gas.
The small holes were processed while flowing at 0 L/min.

After machining 50 pieces, the 11th hole was completed.
J song has 71 holes with an average length of 1 second and 5 small holes with an average diameter of 03.
0 metal holes were drilled.

Example 2 The alumina used in Example 1 was fired. A ring-shaped gas supply body (15 mm thick) was used while changing the average output, frequency, lens focal length, focal depth, nozzle tip distance, auxiliary gas flow rate, and irradiation time as shown in the table below. Ta.

As can be seen from the above table, according to the present invention, 0.2 to 1.0
This method has the advantage of being able to quickly and uniformly process small holes with a hole diameter of about 1.0 m or narrow slits (in a few seconds).

In addition, the plate processed by the present invention was used to make molten metal, and the gas supply was sufficient, and the small pores were not eroded or closed due to melting, compared to conventional processed products. It was excellent.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the laser device, Fig. 2 is an explanatory diagram of the laser device of another example (U example), Fig. 3 is a cross-sectional view of the melting and discharging plate, and Fig. 4 is an explanatory diagram of the laser device of the second embodiment. 1lili plane view of the molten metal r@ discharge plate, FIG. 5 is a Fhi plane view of the molten metal discharge plate of the (It+ embodiment), and FIG. 1... Laser, 2... Lens, 5... Nozzle, 6
...Auxiliary gas through hole, 8...Prism, 9...Small hole (slit) 10...Gas equalization zone, 11...Gas introduction hole. Minister of Procedure? -tE f! April 3, 1980 r2 Patent Office Ryo C Kazuo Wakasugi IFi! ,,t,;,1,Thing 14
Indication of Patent Application IIV158-247242 No. 2, Name of the Invention, Processing Method for Molten Metal Discharging Plate 3, Relationship with Persons Who Will Make Amendments Patent Applicant: 1-26 Nishi-Shinjuku, Shinjuku-ku, Tokyo 160 2 No. 5,
Section 10 Detailed Description of the Invention in the Specification in Subject, Contents of Amendment (1) In Mei M, page 4, line 4, d3, it states, ``The surface has a depth of focus of 1-1. ” and ``The distance to the surface is 11 times the depth of focus.'': J i[. (2) d3 is on page 4, lines 10 to 13 of the specification box,
``In general, tar is the most effective.'' [Although tar is impregnated to improve durability, when laser processing As the laser absorption ability is better than the conventional one, it is possible to drill small holes more efficiently. ” he corrected. (3) On page 5, lines 12-13 of the detailed statement, “
Since the aperture of the focal point 3 is constantly changing, the aperture ratio deteriorates. ``Due to the decrease in pore area ratio due to defocus, it becomes difficult to control the pore diameter from 1 to 10.'' ” and corrected Jro. (4) Mei II appearance number 5618? In the i-th to 19th lines, 1 is replaced by 1 because the flying flit object hits the nozzle 5 and one nozzle 5 gets stuck.
)

Claims (1)

[Claims] A sliding plate or fixed plate for molten metal having small holes or slits for supplying gas into the molten metal, characterized in that the small holes or slits are processed by laser. How to process the delivery plate