JPS6340670A - Molten metal injection nozzle - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This 51 light is easily melted by a sliding nozzle:
The present invention relates to a molten metal injection nozzle that injects molten metal from a molten metal storage container into another container such as a mold while adjusting Ria.

[Prior Art] For example, in continuous casting of steel, conventionally, molten steel stored in a ladle is flowed out into a -H tundish through a ladle nozzle, and this molten steel is passed from the tundish nozzle to the tundish nozzle. It is injected into the mold through. For example, when pouring molten steel into a mold from a tundish, as shown in FIG. The molten steel is injected into the mold 7 through a pair of outflow holes 9a and 9b formed at the tips of the nozzle 6 and the tundish nozzle 6. On the other hand, the sliding nozzle 3 is arranged between a stationary plate 4 fixed to the bottom of the tandice 1, a slide plate 5 provided below the fixed plate 4, and the slide plate 5 and the tandice nozzle 6. By sliding this slide plate 5 together with the collector nozzle 17 and the tandate nozzle 6 in the direction of the arrow 11, the frontage area of the molten steel flow hole 10 is adjusted and the molten steel 2 outflow is controlled.

[Problems to be Solved by the Invention] However, when the sliding nozzle 3 is used to throttle the outflow of molten steel, the slider 5 is moved in the direction of arrow 12, but in this case, the molten steel flow is directed in the direction of arrow 13. It becomes a biased flow. When this separate flow occurs, the molten steel flow once collides with the molten steel collision portion 16 on the inner wall of the tundish nozzle 6, and then flows out. Therefore, the molten steel 2 flows through the molten steel outflow hole 9a,
It does not flow out uniformly from hole 9b, and the flow out from hole 9a becomes larger. Therefore, when the molten steel 114 is poured, the molten steel 1 on the hole 9a side in the mold is stirred, and the powder 1 floating on the molten steel dry surface is stirred.
There is a risk that 5 etc. may become entangled and become inclusions in the steel.

This invention was made in view of such circumstances.
It is an object of the present invention to provide a melt injection nozzle that can eliminate the flow and prevent the mixing of impurities due to stirring of the melt-prone surface.

[Means for Solving the Problems 1] The molten metal injection nozzle according to the present invention has a cylindrical shape and is attached to a molten metal storage container through a sliding nozzle having a fixed plate and a sliding plate. The molten metal injection nozzle injects the molten metal in the molten metal storage container into another container while adjusting the flow rate of the molten metal by moving a slide plate, and the molten metal injecting nozzle injects the molten metal in the longitudinal direction into a region of the inner wall including the portion where the molten metal collides. It is characterized by having a plurality of grooves formed along it. In this case, the groove can be formed so that the horizontal cross section of the region is chrysanthemum-shaped.

[Operation] In the present invention, a plurality of grooves are provided along the longitudinal direction of the ffi region including the portion of the inner wall of the molten metal injection nozzle that the molten metal collides with. Then, as the molten steel flow collides with this groove, the flow velocity of the molten metal flow is relaxed, and the molten steel flows along this groove.

Therefore, drift can be eliminated.

[Embodiments] Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

Fig. 1 is a cross-sectional view showing continuous VC casting when the molten metal injection nozzle according to the present invention is applied to a tundish nozzle in continuous casting. covered with iron skin. 1 g of melt 22 is poured into the tundish 21 from a ladle (not shown). This tandaitsu 21
A molten steel outlet 23 through which molten steel 22 flows out is formed at the bottom. The molten steel outlet 23 is surrounded by porous bricks 24, and between the porous bricks 24 and the refractory lining of the kundish 21, there is a brick 25.
is installed. A copper mold 34 is disposed below the tundish 21 so that its longitudinal direction coincides with the longitudinal direction of the tundish 21, and the steel 22 in the tundish 21 is mainly put into this mold 34 to form a heavy It is now being cast continuously. A sliding nozzle 26 is attached to the hole 23 at the bottom of the tandy dish 21. The sliding nozzle 26 includes a fixed mold 27 attached to the bottom of the kundish 21, a slide plate 28 provided below the fixed plate 27, and a collector nozzle 42 provided below the slide plate 28. By moving the slide plate 28 in the direction of the arrow 29, the molten steel flow hole 30 of the sliding nozzle 26 is opened.
The amount of molten steel flowing out is controlled by adjusting the opening area. A cylindrical tundish nozzle 31 made of refractory material is installed at the lower end of the collector nozzle 42. A molten steel flow passage 33 through which molten steel 22 flows is formed inside the tundish nozzle 31, and a pair of molten XN outflow holes 32a, 32b are formed at the tip thereof. The molten steel 22 flowing out from the molten steel flow path 33 flows through the molten steel outflow holes 32a, 3.
From 2b above! It is adapted to be injected into mold 8 34. In a steady state, the tip of the tundish nozzle 31 including the molten steel outflow holes 32a and 32b8 is immersed in the molten steel in the mold 34. In addition, powder 3G is suspended on the molten m > M surface in the mold 34, which prevents the molten steel in the mold from becoming solid and improves the lubricity between the mold and the molten steel. ing.

A groove forming area 41 in which a plurality of grooves are formed along the longitudinal direction is provided on the upper part of the inner wall of the tandate nozzle 31, and the cross section of this area 41 taken along the line II-II is as follows. As shown in Figure 2, it is chrysanthemum-shaped. Further, this region 41 is formed at a portion where the drift of molten steel that occurs when '+'FJ It has a smaller inner diameter than other parts.

Next, the operation of this embodiment will be explained. First, molten steel 22 is poured into the tundish 21 from a ladle (not shown), and the molten steel tjA22 is poured into the mold through the 5J steel outlet 23 at the bottom of the tundish 21 through the sliding nozzle 26, the tundish nozzle 31, and the molten steel outflow holes 32a, 32b. Inject into 34. Then, the injection amount of m tJ4 is determined by pointing the sliding plate 28 of the sliding nozzle 2G at the arrow 2.
Control is performed by adjusting the opening area of the molten steel flow hole 30 by moving it in nine directions. When the opening area of the molten steel flow hole 30 of the sliding nozzle 26 is narrowed to reduce the amount of molten steel flowing out, the molten steel flow becomes a drift flow and collides with the groove forming region 41 of the inner wall of the sliding nozzle 31. In this case, since a plurality of grooves are formed in this region 41 along the longitudinal direction of the nozzle 31 so that the cross section is chrysanthemum-shaped, even if the molten steel flow becomes uneven, the arrow 40 As shown, as the molten steel flow collides with this region 41, the flow velocity of the molten steel flow is relaxed, the molten steel flow flows along the groove, and the drifting flow is subsequently eliminated. Therefore, the molten steel outflow hole 32a
, 32b can uniformly flow out of the molten steel, and the powder 36 can be prevented from becoming entangled. Also, area 4
1 has a smaller inner diameter than the other parts, a step is formed between the region 41 and the pond part, and the molten steel flow collides with this step, which has the effect of moderating the flow velocity of the molten steel flow. It gets even bigger.

Next, the effects of this embodiment will be specifically explained. FIG. 2 is a graph showing the relationship between the amount of blown argon and the one-sided flow evaluation value, with the horizontal axis representing the blown argon gas collapse and the vertical axis representing the one-sided flow evaluation value. Here, the blown argon is supplied into the tundish nozzle for the purpose of preventing nozzle clogging. In addition, the one-sided flow evaluation value indicates the non-uniformity of the molten steel flow flowing out from the molten steel outflow holes 28a and 28b, and A indicates the case where the molten steel flows out uniformly, and B
C indicates a case where a slight one-sided flow occurs, and C indicates a case where a severe one-sided flow occurs. In the figure, white circles indicate the case of this embodiment, and black circles indicate the conventional example. According to this, in the case of the conventional example, one-sided flow occurs at nearly half the rate regardless of the amount of blown argon gas, whereas in the case of the example, when the amount of blown argon gas exceeds 7ρ/min. It can be seen that no one-sided flow occurs.

FIG. 3 is a graph showing the relationship between the molten steel discharge surface and the one-sided flow rate, with the horizontal axis representing the molten steel discharge amount and the vertical axis representing the one-sided flow rate. Here, the one-sided flow rate is calculated from the electric distribution generated in the width direction of the argon gas residual bubbles confirmed by sulfur printing of the slab.For example, if the number of residual bubbles on both sides from the center is the same, the one-sided flow rate is is 0 and there are residual bubbles only on one side, the one-sided flow rate is 10
It is 0%. Further, in the figure, white circles indicate the case of this embodiment, and black circles indicate the case of the conventional example. According to this, it can be seen that in both the example and the conventional example, the one-sided flow rate increases as the discharge amount of molten steel decreases, but the one-sided flow rate is lower in the example as a whole than in the conventional example. These results confirmed the effectiveness of this example.

In this embodiment, the present invention is applied to a tundish nozzle, but the present invention is not limited thereto, and can also be applied to, for example, a steel nozzle.

[Effects of the invention] According to this invention, a plurality of grooves are provided along the longitudinal direction in the portion of the inner wall of the molten metal injection nozzle where the molten metal collides, so even if the molten metal flow becomes 0; As the molten metal flow collides with the groove, the flow velocity of the molten metal flow is relaxed, and
Molten steel flows along the groove, 51! The trailing drift is eliminated. Therefore, the molten metal and F2 can be uniformly flowed out from the molten metal through the molten metal, and impurities can be prevented from being mixed into the molten metal.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a continuous casting apparatus in which a melt layer injection nozzle according to the present invention is applied to a tandate nozzle;
Fig. 2 is a sectional view showing an iU4 injection nozzle according to an embodiment of the present invention, Figs. 3 and 4 are graphs showing the effects of this invention, and Fig. 5 is a cross-sectional view showing an iU 4 injection nozzle according to an embodiment of the present invention. FIG. 2 is a sectional view showing a continuous casting device. 21: Tandaitsu, 26; Sliding nozzle,
31; Tanditshu nozzle, 32a. 32b; Molten steel outflow hole, 33: Molten steel flow path, 41; Groove forming area, 34; Mold applicant's representative Patent attorney Takehiko Suzue Figure 2 Figure 3 Melting y4 Puto Mizu (Tonl Shu) Figure 4 Figure 5

Claims (2)

[Claims] (1) It is attached to the molten metal storage container via a sliding nozzle that has a cylindrical shape and has a fixed plate and a sliding plate,
In the molten metal injection nozzle, which injects the molten metal in the molten metal storage container into another container while adjusting the flow rate of the molten metal by moving the sliding plate of the sliding nozzle, the molten metal is injected into the area of the inner wall including the portion where the molten metal collides. A molten metal injection nozzle characterized in that a plurality of grooves are formed along the longitudinal direction. (2) The molten metal injection nozzle according to claim 1, wherein the groove is formed so that the horizontal cross section of the region is chrysanthemum-shaped.