JPS6099460A - Device for discharging molten metal - Google Patents

Abstract

PURPOSE:To prevent surely clogging of a passage hole for a molten metal by providing a gaseous pressure equalizing zone and a gas introducing hole communicating with said zone to the inside of a stationary plate and providing slits communicating with the gaseous pressure equalizing zone and the passage hole to the stationary plate. CONSTITUTION:An upper stationary plate 21 formed of dense refractories is provided internally with an annular gaseous pressure equalizing zone 24 in the position apart at a prescribed distance from the slide face with a slide plate 22. A gas introducing hole 25 communicating with the zone 24 is provided to the plate 21 and a gas introducing pipe 26 is connected thereto. Slits 27... connecting the zone 24 and a passage hole are further provided to the plate 21. Gas having a large bubble diameter is thus uniformly controlled in any position and is supplied through the slits 27... and therefore the clogging of the passage hole is surely prevented.

Description

[Detailed description of the invention]

This article relates to a molten metal discharge device that is placed at the bottom of a ladle or tumbler when molten metal is cast. For example, when producing molten steel using the continuous spinning method, a molten metal discharge device consisting of a fixed plate and a moving plate (slide) is attached to the nozzle at the bottom of the ladle or tumble pusher that contains the molten steel.

[) By sliding the slide plate relative to the fixed plate, the passage hole for molten steel is opened and closed, and the concentration of the molten steel is adjusted]1]. In the above-mentioned molten metal discharge device, the molten steel passage hole is used to solidify molten steel, AI, Ti
Ar is added from the fixed plate into the molten steel to prevent oxides of metals such as , Ca, Cr, and Ni from clogging up.
It is practiced to supply inert gas such as. Such a conventional molten metal 1j1 outlet neck will be explained with reference to FIG. In the figure, 'l' is an upper nozzle fixed to the bottom of a tongue pusher (not shown) and having a passage hole for 78 molten metal. Below the upper nozzle 1, there is installed a molten metal discharge device consisting of an upper fixed plate 2, a slide Q83, and a lower fixed plate 4 each having a passage hole for molten metal. The slide plate 3 opens and closes the passage hole by sliding between the upper fixed plate 2 and the lower fixed plate 4, thereby adjusting the flow m of molten steel and completely closing the passage hole. The main body of the upper fixed platen 2 is made of a dense m-sized material, and a gas supply body 5 made of a porous refractory is fitted around the entire circumference on the inner wall surface of the upper part. A waste pressure equalizing zone 6 is provided between the two. Further, a gas introduction hole 7 is formed in the upper fixed platen 2 and communicates with the gas equalization zone 6, and a gas introduction pipe (not shown) is connected thereto. An immersion nozzle 8 is attached below the lower fixed plate 4, and the lower end of the immersion nozzle 8 is inserted into a mold 9. In the above device, the molten steel in the tongue push (not shown) is sent to the mold 9 through the passage holes in the upper nozzle 1 , the upper fixed plate 2 , the slide plate 3 , the lower fixed plate 4 and the immersion nozzle 8 . and is cooled at its lower part. As a result, a molten layer 10, a semi-molten layer 11, and a solidified layer 12 are formed inside the mold 9 and beyond. In addition, molten layer 1
0, mold powder 13 is provided. In the above device, when the supply of molten steel from the ladle to the tundish starts, the molten steel is solidified in the passage hole of the upper fixed plate 2 by supplying scraps into the molten steel through the gas supply body 5 and stirring the molten steel. This prevents this and facilitates initial opening. In addition, by supplying scraps and stirring the molten steel during casting,
Prevents solidification of molten steel and adhesion of oxides, and prevents clogging of passage holes. Furthermore, by supplying gas to float oxides in the molten steel, the number of oxide inclusions in the steel is reduced to 1/5 to 1/10 compared to products in which no dregs are supplied. However, in the conventional molten metal discharge device described above,
Since the gas supply body 5 made of a porous refractory is used to supply gas into molten steel, there are the following drawbacks. (a) iE; Since the bubble diameter of the dregs supplied into jM is small, the stirring force is small, and it cannot be said that clogging of the passage holes can be reliably prevented. (b) Since the gas supply body 5 is porous, its corrosion resistance is poor. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a molten metal discharge device that can more reliably prevent clogging of molten metal passage holes and improve corrosion resistance against molten metal. . The molten metal discharge device of the present invention has a fixed plate made of a dense refractory, a gas equalizing zone and a gas introduction hole communicating with the gas equalizing zone inside the fixed plate, and a scum equalizing zone and a molten metal discharging device in the fixed plate. It is characterized by providing a plurality of sulins 1- which communicate with the metal passage holes. According to such a molten metal discharging device, waste having large bubble diameters can be uniformly controlled and supplied to any position from a plurality of slits, so that blockage of the passage hole can be reliably prevented. Furthermore, since the wall surface of the passage hole is made of a dense refractory material, corrosion resistance against molten metal is also improved. In addition, in this Komei, the cross-sectional dimension of the slit is 0.1 in width.
It is preferable that the diameter is 0.5 mm and the height is 1 to 5 mm. This means that the cross-sectional dimensions of Surin 1~ are 0 and 1 m horizontally.
This is because if the diameter is 0.5111111 or R without a vertical 1 mm vortex, the amount of debris supplied will be small and the effect of preventing clogging of the passage hole will be reduced.
If the thickness exceeds 5 mm, it will melt inside! This is because metal enters and causes clogging. Hereinafter, embodiments of the present invention will be described with reference to FIG. Figure 2 shows upper fixed plate 2 each having a passage hole for molten metal.
1. A molten metal discharge device consisting of a slide plate 22 and a lower fixed plate 23 iJ+. The upper stationary platen 21 is made of a dense, durable material, and inside thereof is an annular waste pressure equalizing zone 24 with a width of 2 mm and a height of 25 mm from a position 15 mm apart from the sliding surface with the slide plate 22. is provided. Further, a waste introduction hole 25 communicating with the waste equalization zone 24 is provided in the upper fixed plate 21, and a gas introduction pipe 26 is connected thereto. Furthermore, the top is fixed! 21 is the waste equalization zone 24
hio, 2 mm, fti (5
mm sleeve l-27. ...10 pieces within the circumference, the longitudinal direction parallel to the axis of the passage hole, 3 rows up and down, 30fl pewter! j Arranged and set ()
I'm here. The above device for discharging four molten metals is similar to the conventional molten metal discharging device shown in FIG. ; Sadanosuru is taken and used. Note that the scum pressure equalizing band 24 and the slit 27 inside the upper fixed male 121. ... is a waste equalization zone 24 in the clay on the side of the molding.
and Surin 1-27, . . . were embedded in a predetermined position and burned out in the firing process. Note that Surin I-27, . . . may be provided by ultrasonic processing, laser processing, etc. after firing. Further, the waste introduction hole 25 was formed by drilling after firing. However, if the above-mentioned molten metal discharge device J:
Since the gas with large bubble diameter is uniformly controlled and supplied to any position through the passage holes 27, . . . , it is possible to reliably prevent the passage holes from being blocked. Furthermore, since the inner surface of the upper fixed platen 21 is also made of dense refractory material, it has good corrosion resistance against molten metal. In fact, from a ladle with a volume of 160 tons, Sol, A1.0゜0
35% aluminum killed steel is continuously injected fi3
The conventional molten metal discharge device and the molten metal discharge device of the above embodiment were installed in the upper nozzles of two strands of a 0t, 4-strand tundish, respectively, and continuous casting was carried out at /υ, and the following results were obtained. It was done. First, the passage hole of the molten metal discharge device was closed, and molten steel was injected from the steel plate into the tundish while blowing Ar gas at 150 ffl/min. When the height of the molten steel in the tundish reached approximately 60 cm, the passage hole of the molten metal discharge device was opened. At this time, one of the conventional molten metal discharge devices did not allow molten steel to flow out and required oxygen cleaning. After that, it was time for Arkasu! The amount of molten steel is adjusted to 106/'m111 and 1 wI of molten steel is continuously poured/υ. In the latter half of the sixth pot, each molten metal discharge device became in a state where the flow rate of molten metal to the mold was insufficient for the predetermined casting speed.
In order to remove the blockage in the passage hole, the supply rate of Ar gas was temporarily increased to 50A/min, and then again to 10A/min.
I returned it to A'7 m r n. At this time, the molten steel flow rate returned to normal in the strand in which the molten metal discharge device of the example was incorporated, but in the strand in which the conventional molten metal discharge device was incorporated, the molten steel flow rate gradually decreased and casting became impossible. It became a state. This is because in the conventional molten metal discharge device, the force of stirring the molten steel by the scum is small, so it cannot effectively prevent the passage hole from clogging, whereas in the molten metal discharge 1fiff of the above embodiment, the force of stirring the molten steel by the gas is large. This is thought to be because the passage hole can be reliably prevented from being blocked. In addition, in the above embodiment, there is a width of 0°2 m inside the upper fixed plate 21.
Although the sleeves 1 to 1 with dimensions of 5 mm in width and 5 mm in length were formed, the dimensions of the sleeve i can be arbitrarily selected within the range of 0 mm in width, 1 to 0 mm in width, and 1 to 5 mm in length. Furthermore, the slits may be arranged so that their longitudinal direction is parallel to the sliding surface. In addition, in the above embodiment, the sulins 1 to 2 are directly attached to the upper fixed platen 21.
7. ... was installed, but as shown in Figure 3, the upper fixed plate 2
Slabs 1 to 27.1 form a waste pressure equalizing zone 24 with the upper fixed platen 21 at the center of the gas pressure equalizing zone 24 and communicate with the molten metal passage hole. It is also possible to have a structure in which one gas supply body 28 formed in the following manner is attached. Furthermore, the sleeve 1- may be provided only in the range of 1/3 to 2/3 of the circumference on the inner wall surface of the upper surface plate passage hole on the opposite side to the moving direction of the moving plate 18 in the passage hole closing section. good. In other words, in the continuous &yi production method, the molten metal discharging device must withstand long-time casting, so that each fffi oxide adheres to the wall surface of the passage hole.
In order to maintain this, the cross-sectional area of the passage hole is designed to be 3.5 to 4.5 times the required flow rate of molten steel, and the opening degree of the passage hole at the initial stage of casting is set to 35 to 45%. We are doing a narrowing down. In this case, the flow of molten steel is extremely poor in the area surrounded by the top surface (closed part) of the slide plate and the inner wall surface of the upper fixed plate, so in this area, 'tT
The JKM loses heat to the surrounding refractories and is cooled to a semi-molten state, which in turn invites oxides and becomes more likely to become clogged. Therefore, it is necessary to stir by feeding the dregs ('81!), but if the dregs are supplied from the entire circumference of the passage hole,
Excess gas may be drawn into the molten steel and press-fit into the mold, entraining the mold paraphernalia, or causing gas-induced pinholes in the solidified layer within the mold, resulting in defective steel. be. On the other hand, if Surin 1- is provided in the above-mentioned range of the inner wall of the upper fixed plate, and the amount of Surin 1- is reduced at the position where the passage hole is surrounded by -C during squeeze pouring, the supplied gas will be excessive. The passage hole can be covered to prevent clogging without being drawn into the mold. If the range in which d5 and Surin 1- is provided is less than 1/3 of the circumference, the amount of debris will be small and the effect of preventing clogging of the passage hole will be small; on the other hand, if it exceeds 27/3, excess debris will be drawn into the mold. This can lead to defective steel. In addition, in the above explanation, the molten metal discharging device is composed of an upper fixed type, a sliding plate, and a lower fixed plate.
Regarding the molten metal discharge device, which consists of a slide plate that slides against this fixed plate, and a immersion nozzle installed below the slide plate, the molten metal discharge device moves all at once. The fixed plate may have a structure similar to the upper fixed plate of the above embodiment.Furthermore, the molten metal discharge device of the present invention can of course be installed not only at the bottom of the tundish but also at the bottom of the steel plate. As detailed above, in the molten metal discharge device of the present invention,
This provides significant effects such as being able to reliably prevent clogging of the passage hole for molten metal and improving corrosion resistance against molten metal.

[Brief explanation of the drawing]

Figure 1 shows a conventional molten metal discharge device installed in a continuous casting machine.
FIG. 2 is a sectional view of a molten metal discharging device according to an embodiment of the present invention, and FIG. 3 is a sectional view of a molten metal discharging device according to another embodiment of the present invention. . 21... Upper fixed ΩA, 22... Slide arm, 23.
... Lower fixed plate, 211 ... Kass pressure equalization zone, 25 ... Kass gully hole, 26 ... Kass lJ4 supply pipe, 27 ... Surin 1~. 28... Dregs supply body. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A molten metal discharge device having a fixed plate attached to a nozzle at the bottom of a container containing molten metal, and a sliding plate that opens and closes a passage hole for molten metal by sliding with respect to the fixed plate, The fixed plate is made of a dense and durable material, and inside the fixed plate there is a waste pressure equalization zone and a gas introduction hole communicating with this zone.
A molten metal discharge device characterized in that the fixed plate is provided with a plurality of slits that communicate the 10,000-thick pressure equalization zone with the molten metal passage hole.