JP3743556B2 - Plate refractory for sliding nozzle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sliding nozzle plate refractory that controls the outflow amount of molten metal at a spout part of a molten steel processing facility, and more particularly to a sliding nozzle plate refractory in which both end surfaces and both side surfaces of the plate are arc-shaped.
[0002]
[Prior art]
Generally, a sliding nozzle plate refractory for adjusting the outflow amount is provided at a molten metal spout portion in a continuous casting facility.
[0003]
As shown in FIG. 5, the sliding nozzle plate refractory 11 (12, 13) is incorporated in a continuous casting facility, and the continuous casting facility is fixed to the bottom of the tundish or ladle 21. The gate device main body 22 is provided with a fixed plate refractory support member 23 and a movable plate refractory support member 24 which overlaps with the fixed plate refractory support member 24. The movable plate refractory support member 24 is slid by the operation of the cylinder 27 supported outside the gate device main body 22 and is moved to one side in the longitudinal direction of the plate refractory 11. The outflow amount of the molten metal is controlled by changing the alignment position of the nozzle hole 14 formed by being biased.
[0004]
As shown in FIG. 6, the conventional plate refractory 11 generally has an octagonal shape, and has both longitudinal side surfaces 11a, longitudinal linear end surfaces 11b, 11c, and It is formed from an inclined surface 11d inclined at a predetermined angle from both side surfaces 11a.
[0005]
In the plate refractory 11 having such a shape, a frame-like iron hoop (hoop) 15 is shrink-fitted around the outer periphery of the plate, thereby preventing the enlargement of cracks during use and giving consideration to safe use. However, the tightening (fixing) has a structure in which the frame-shaped iron skin 15 and the both side surfaces 11a, both end surfaces 11b and 11c and the inclined surface 11d of the plate refractory 11 are brought into close contact with each other.
[0006]
[Problems to be solved by the invention]
However, since the eight corner portions 11e protrude, the frame-shaped iron skin 15 and the both side surfaces 11a, both end surfaces 11b and 11c, and the inclined surface 11d are not in close contact with each other, and the binding force tends to be weakened. The portion 11e is in close contact and stress concentrates on the corner portion 11e. Accordingly, if a crack occurs due to the impact force generated by the thermal stress and flow velocity from the molten steel flowing through the nozzle hole 14, the expansion of the crack cannot be suppressed due to the lack of the restraining force of the frame-shaped iron skin 15, and it is concentrated on the corner 11e. It was often observed that the stress (indicated by the double line arrow in FIG. 6) acts in the direction of expanding the crack, so that the crack expands and the life of the plate refractory 11 is reduced.
[0007]
Accordingly, there is a need for a long-life sliding nozzle plate refractory that can prevent the crack from expanding. The present invention has been made in consideration of the above-described circumstances, and the long-life sliding nozzle plate that can prevent the crack from expanding. The purpose is to provide refractories.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention of claim 1 of the present application includes a plate refractory having nozzle holes formed by controlling the outflow amount of molten metal and being biased in one of the longitudinal directions, and the plate refractory. In a plate refractory for a sliding nozzle having a frame-like iron skin fitted in a peripheral surface portion of an object and used by being advanced and retracted in the longitudinal direction of the plate refractory, the plate refractory includes both side surfaces in the longitudinal direction. and arcuate portions are provided on both end faces, a circular arc portion of said both side faces Ri the radius of curvature is 100~10000mm der, arcuate portion of the longitudinal end surfaces located closer to the nozzle hole radius of curvature 40~130mm Of the two end faces in the longitudinal direction, the gradient of the inclined portion close to the nozzle hole is set to 1: 1 to 1: 3, and the gradient of the inclined portion far from the nozzle hole is set to 1: 2 to 1: 5. To Is summarized in that a plate refractories for Lee loading nozzle.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a fluid machine according to the present invention will be described below with reference to the accompanying drawings.
[0012]
FIG. 1 is a plan view of a sliding nozzle plate refractory according to the present invention.
[0013]
As shown in FIG. 1, a sliding nozzle plate refractory 1 is inserted into a plate refractory 3 provided with a nozzle hole 2 for controlling the outflow amount of molten metal, and a peripheral surface portion of the plate refractory 3. It has a frame-shaped iron skin 4 (hoop).
[0014]
The plate refractory 3 is provided with arc portions 3a on both side surfaces thereof, and the arc portion 3a has a radius of curvature of 100 to 10000 mm, and the end surface on the side close to the nozzle hole 2 in the longitudinal direction (the anti-stroke side). Is provided with an arc portion 3b, and an arc portion 3c is also provided on an end surface on the side far from the nozzle hole (stroke side). The radius of curvature of the arc portion 3b is 40 to 130 mm. If this radius of curvature is less than 40 mm, stress concentrates on this arc portion and cracks are likely to occur, and stress is directed in the direction of expanding the cracks, and the cracks expand. If it exceeds 130 mm, it becomes close to a straight line, and tightening with a frame-shaped iron skin is insufficient, so that expansion of cracks cannot be suppressed. The radius of curvature of the arc portion 3c is 30 to 120 mm.
[0015]
Further, the arc portion 3a and the arc portion 3b are connected by a linear surface to form a slope portion 3d on the side close to the nozzle hole 2, and the arc portion 3a and the arc portion 3c are connected by a linear surface. Thus, a slope portion 3e on the side far from the nozzle hole 2 is formed. The slope portion 3d on the side close to the nozzle hole 2 has a steeper slope than the slope portion 3e on the side far from the nozzle hole 2, and the slope (w / l) of the steep slope portion 3d has a ratio of 1: 1 to 1. : 3, and the slope portion 3e having a gentle slope has a slope (W / L) of 1: 2 to 1: 5. If the steep slope (w / l) is outside the range of 1: 1 to 1: 3, the length l of the inclined surface portion 3d becomes too short, and stress tends to concentrate on the arc portion 3a and the arc portion 3b, or The length l of the slope portion 3d becomes too long and the tightening force becomes insufficient. Further, if the gentle gradient (W / L) is out of the range of 1: 2 to 1: 5, the length l of the inclined surface portion 3e becomes too short, and stress is easily concentrated on the arc portion 3a and the arc portion 3c. Alternatively, the length l of the slope portion 3e becomes too long and the tightening force becomes insufficient.
[0016]
The plate refractory 3 is surrounded by the frame-shaped iron skin 4 and is shrink-fitted by the frame-shaped iron skin 4. Since the plate refractory 3 has the shape as described above, the restraining force (clamping force) by the frame-shaped iron skin 4 is applied to the plate refractory 3 via the arc portions 3a, 3b, 3c and the inclined portions 3d, 3e. It is in an almost uniform state as compared with the prior art.
[0017]
Next, a method for using the sliding nozzle plate refractory according to the present invention will be described.
[0018]
A sliding nozzle plate refractory 1 as shown in FIG. 1 is mounted on a gate device body as shown in FIG.
[0019]
As shown in FIG. 2, the sliding nozzle plate refractory 1 has a tightening stress (indicated by an arrow in FIG. 2) due to the frame-shaped iron skin 4 through the arc portions 3a, 3b, 3c and the inclined portions 3d, 3e. Even if cracks occur due to the impact force generated by the thermal stress and flow velocity from the molten steel flowing through the nozzle hole 2, the expansion of the cracks is suppressed, and each arc part 3a, 3b In addition, since the slope portions 3d and 3e have a predetermined slope, the plate refractory 3 is uniformly applied with a tightening stress to reduce the expansion of cracks (double line in FIG. 2). Acting on the arrow), the expansion of cracks can be suppressed. Accordingly, the life of the sliding nozzle plate refractory 1 can be extended.
[0020]
【Example】
Using the sliding nozzle plate refractory according to the present invention having the shape as shown in FIG. 3 and the conventional sliding nozzle plate refractory as shown in FIG. 6, the test was conducted under the following conditions.
[0021]
Test conditions Ladle capacity: 150 tons, casting time: 60 minutes / time, operating temperature: 1600 ° C
Results Shown in FIG. 4 (Example) and FIG. 7 (Conventional example).
[0022]
In the example, the cracks expanded as shown in FIG. 4 after 7 uses. On the other hand, in the conventional example, the expansion of cracks as shown in FIG. 7 was observed.
[0023]
The example can be used once more than the conventional example.
[0024]
【The invention's effect】
According to the sliding nozzle plate refractory according to the present invention, it is possible to provide a sliding nozzle plate refractory that can prevent the crack from expanding.
[0025]
That is, the plate refractory is provided with arc portions on both end surfaces and both side surfaces in the longitudinal direction, and the arc portions on the both side surfaces have a radius of curvature of 100 to 10000 mm. ) Acts evenly on the plate refractory to suppress the expansion of cracks, and acts in the direction of reducing the expansion of cracks to suppress the expansion of cracks.
[0026]
Further, since the arc portion of the longitudinal end surface located on the side close to the nozzle hole has a radius of curvature of 40 to 130 mm, it can be dispersed while avoiding the concentration of restraining force by the frame-shaped iron skin, and the expansion of cracks is suppressed, In addition, the crack can be prevented from expanding by acting in a direction to reduce the expansion of the crack.
[0027]
Moreover, since the gradient of the inclined part near the nozzle hole is 1: 1 to 1: 3 and the gradient of the inclined part far from the nozzle hole is 1: 2 to 1: 5 among both end faces in the longitudinal direction, each arc part Further, it is possible to suppress the expansion of the crack by applying the tightening stress to the plate refractory uniformly through the inclined portions, and to suppress the expansion of the crack by acting in the direction of reducing the expansion of the crack.
[Brief description of the drawings]
FIG. 1 is a plan view of a sliding nozzle plate refractory according to the present invention.
FIG. 2 is a plan view showing a usage state of a sliding nozzle plate refractory according to the present invention.
FIG. 3 is a plan view showing a usage state of the sliding nozzle plate refractory according to the present invention used in the test of the embodiment.
FIG. 4 is a plan view showing a state after the test of the sliding nozzle plate refractory according to the present invention used in the test of the embodiment.
FIG. 5 is a cross-sectional view of a general gate device body.
FIG. 6 is a plan view of a conventional sliding nozzle plate refractory.
FIG. 7 is a plan view showing a state after the test of the conventional sliding nozzle plate refractory used in the test of the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sliding nozzle plate refractory 2 Nozzle hole 3 Plate refractory 3a Arc part 3b Arc part 3c Arc part 3d Slope part 3e Slope part 4 Frame-shaped iron skin (hoop)

Claims (1)

It has a plate refractory provided with a nozzle hole formed to control the outflow amount of the molten metal and biased to one side in the longitudinal direction, and a frame-shaped iron skin inserted into the peripheral surface portion of the plate refractory In the plate refractory for sliding nozzles used by advancing and retreating in the longitudinal direction of the plate refractory, the plate refractory is provided with arc portions on both side surfaces and both end surfaces in the longitudinal direction. Ri the radius of curvature 100~10000mm der, arcuate portion of the longitudinal end surfaces located closer to the nozzle hole is the radius of curvature is 40～130Mm, inclined portion close to the nozzle hole of the end faces of the longitudinal The sliding nozzle plate refractory is characterized in that the gradient is 1: 1 to 1: 3 and the gradient of the inclined portion far from the nozzle hole is 1: 2 to 1: 5 .

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