JP2011088214A - Slide gate plate and regenerating method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a slide gate plate for regenerating, wherein the crack is hardly generated from the surrounding of an exchanging brick. <P>SOLUTION: The method is performed through the following process of forming the through hole 24 of a plate 23 in such a manner that the taper angle θ at the inside is made higher than 0° and also lower than 45° to a line vertical to one side or the other side of a base body brick 23b, preparing an exchanging brick 25 having a body part 25a with a shape of being provided with a taper face free from stage error in the thickness direction at the outer circumference and inserted into the through hole 24, a projecting part 25b extending from a narrow range end part of the body part 25a and a molten metal passing-through hole 23a penetrating the projecting part 25b and the body part 25a, inserting the projecting part 25b of the exchanging brick 25 into the through hole 24 by inserting the projecting part 25b of the exchanging brick 25 from a large hole end part of the through hole 24 in the plate 23 and projecting this part from a small hole end part, and grinding the wide range end part of the exchanging brick 25 inserted into the through hole 24. The taper angle of the taper face in the through hole 24 is made wider whenever the frequency of regenerating increases. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a slide gate plate and a regeneration method thereof, and more particularly to a slide gate plate of a molten metal amount control device used for molten metal discharge control and a regeneration method thereof.

  A flow rate control device for controlling the flow rate of the molten metal is attached to the molten metal discharge port of the bottom iron skin of the molten metal pan, and a slide gate plate 101 as illustrated in FIG. Is attached.

  The slide gate plate 101 includes an upper plate 102 and a lower plate 103 made of a refractory material. Molten metal passage holes 102a and 103a are formed in the upper and lower plates 102 and 103, respectively, and protrusions 102b and 103b projecting to one side are formed around the molten metal passage holes 102a and 103a.

  The upper plate 102 and the lower plates 102 and 103 are used by being overlapped so that the surfaces without the protrusions 102b and 103b contact each other. Then, the flow rate of the molten metal supplied from the nozzle (not shown) is controlled by sliding the lower plate 103 in an overlapped state and adjusting the relative positions of the upper and lower molten metal passage holes 102a and 103a. .

  The slide gate plate 101 is pressed against each other to prevent leakage of molten metal from between the upper and lower plates 102 and 103 as well as a force for relatively sliding the upper and lower plates 102 and 103. Power is applied.

  By the way, the molten metal passage holes 102a and 103a of the upper and lower plates 102 and 103 are in contact with the molten metal at a high temperature, so that the molten metal passage holes 102a and 103a and their surroundings are damaged by receiving heat. In general, the gate plate 101 is discarded after a certain period of use.

  However, the damage received by the upper and lower plates 102 and 103 is the molten metal passage holes 102a and 103a in contact with the molten metal and the periphery thereof, and the other portions are less damaged.

  Therefore, the following Patent Documents 1 to 3 describe that the molten metal passage holes 102a and 103a and the periphery of the upper and lower plates 102 and 103 are partially exchanged and reused.

  In Patent Document 1, as shown in FIG. 11, the molten metal passage holes 102a and 103a formed in the upper plate 102 and the lower plates 102 and 103 and the periphery thereof are hollowed out into a cylindrical shape to form a cylindrical through hole 104. It is described that an annular replacement brick (annular ring) 105 is inserted and fixed in this through hole 104. In this case, the through-hole 104 has a smaller diameter than the protrusions 102a and 103a shown in FIG. 10, and the protrusions 102a and 103a left after being cut out are scraped off. In addition, a protrusion 105b having a larger diameter than the through hole 104 is formed at one end of the annular replacement brick 105, and the protrusion 105b has the same shape as the protrusions 102b and 103b of the initial upper and lower plates 102 and 103. In the center, a molten metal passage hole 105a is formed.

  In Patent Document 2, as shown in FIG. 12, the diameter of the through hole 104 of the upper and lower plates 102 and 103 is made larger than the diameter of the projection 105b of the annular replacement brick 105, and the diameter of the through hole 104 is further increased. It is described that a step 106 is provided by changing one step in the thickness direction, and a step is also provided on the outer peripheral surface of the annular replacement brick 105. This prevents the annular replacement brick 105 from shifting in the thickness direction in the through hole 104.

  Furthermore, in Patent Document 3, as shown in FIG. 13, the diameter of the through holes 104 of the upper and lower plates 102 and 103 is made larger than the diameter of the projection 105 b of the annular replacement brick 105, as in Patent Document 2, In addition, it is described that a step 106 is provided on the inner surface of the through-hole 104 and a tapered surface 107 is provided on the step 106. The tapered surface 107 is provided to prevent the annular ring 105 from shifting in the plate sliding direction within the through hole 104.

JP-A-8-57631 JP 2003-181626 A JP-A-9-2256281

  When the molten metal starts to protrude from the molten metal pan (not shown) and the opening operation of the slide gate plate 101 is started, the pressure of the molten metal, that is, the molten steel pressure acts on the lower annular exchange brick 105. According to the slide gate plate 101 shown in FIG. 5, the lower cylindrical annular replacement brick 105 is easily displaced in the thickness direction. This is because the strength of the mortar that joins the lower annular replacement brick 105 and the lower plate 103 is not sufficiently obtained. Further, as shown in FIG. 11, a gap S is formed between the lower annular replacement brick 105 and the upper plate 102 due to the deviation, and the molten metal leaks through the gap S or the plate slides due to the leaked molten metal. Can cause disability.

  On the other hand, according to the slide gate plate 101 as shown in FIG. 12, the difference in the thickness direction of the annular replacement brick 105 in the lower plate 103 is hardly caused by the step 106. However, since the step 106 is formed in the lower plate 103 that does not have a sufficient thickness, the strength of the plate below the step 106 is reduced, so that when the molten steel pressure is applied to the annular replacement brick 105, the thickness is thin. Stress concentrates on a region, particularly a portion where the corner of the annular exchange brick 105 hits, and a crack 110 is generated. As the annular exchange brick 105 is damaged, molten steel leaks easily through the crack 110.

  Further, in the slide gate plate 101 as shown in FIG. 13, since the step 106 is formed in the lower plate 103 having no sufficient thickness, the strength of the plate below the step 106 is lowered, so that FIG. Similarly, crack 110 is generated in a thin region, and molten steel leakage is likely to occur. In particular, since the pressure concentrates on the tapered surface 107 having a small area in the step 106, when the molten steel pressure is applied to the annular replacement brick 105, the stress is applied to the portion where the corner of the tapered surface 107 hits the thin region. The cracks 110 are concentrated and the molten steel leaks easily through the cracks 110 as the annular exchange brick 105 is damaged.

  Note that the slide gate plate can be reused several times, but the number of reuses is reduced by the occurrence of cracks.

  An object of the present invention is to provide a slide gate plate in which cracks are unlikely to enter from around a replacement brick and a method for manufacturing the same.

  A method for regenerating a slide gate plate according to the present invention for solving the above-described problem is a through-hole having a continuous tapered surface having no step in the thickness direction in the region including the molten metal passage portion of the base brick of the plate. A hole is formed so that the taper angle θ of the inner surface of the through hole is greater than 0 ° and not more than 45 ° with respect to a line perpendicular to one surface or the other surface of the base brick. A main body having a tapered surface on the outer periphery and fitted into the through-hole, a protrusion extending from a narrow end of the main body, and a molten metal passing through the protrusion and the main body. An exchange brick having a hole is prepared, and the projection of the exchange brick is inserted from the large end of the through hole of the plate and protrudes from the small end, so that the replacement brick is fitted into the through hole, and the penetration And a step of polishing the wide end of the replacement bricks fitted in, characterized in that to increase the taper angle of said tapered surface of said through hole in each views increases.

  According to the present invention, the joint surface between the plate and the replacement brick is a continuous tapered surface with no step in the thickness direction. Therefore, there is no acute angle portion on the inner surface of the through-hole of the plate, and the force applied to the plate through the replacement brick is almost equal at any position on the inner wall of the through-hole, thereby avoiding the application of a load locally. Generation of cracks in the plate can be suppressed.

FIG. 1 is a schematic configuration diagram of a molten metal flow rate control device in which a slide gate plate according to an embodiment of the present invention is incorporated. 2A and 2B are a plan view and a sectional view showing an initial state of the slide gate plate according to the embodiment of the present invention. 3 (a) to 3 (c) are cross-sectional views showing a slide gate plate regeneration process according to an embodiment of the present invention. FIG. 4 is a plan view showing a regenerated slide gate plate according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing a usage state of the regenerated slide gate plate according to the embodiment of the present invention. FIG. 6 is a cross-sectional view showing the second and subsequent processing states of the lower plate constituting the regenerated slide gate plate according to the embodiment of the present invention. 7A and 7B are a plan view and a cross-sectional view showing another example of the regenerated slide gate plate according to the embodiment of the present invention. FIG. 8 is a plan view showing still another example of the regenerated slide gate plate according to the embodiment of the present invention. 9 (a) and 9 (b) are cross-sectional views showing other examples of through holes in the regenerated slide gate plate according to the embodiment of the present invention. FIG. 10 is a cross-sectional view showing a general slide gate plate incorporated in the molten metal flow rate control device. FIG. 11 is a cross-sectional view showing a slide gate plate regenerated by the first prior art. FIG. 12 is a cross-sectional view showing a slide gate plate regenerated by the second prior art. FIG. 13 is a cross-sectional view showing a slide gate plate regenerated by the third prior art.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a molten metal flow rate control device in which a slide gate plate according to an embodiment of the present invention is incorporated, and FIGS. 2 (a) and 2 (b) are a plan view and a cross-sectional view of the initial slide gate plate. is there.

  In FIG. 1, a molten metal flow rate control device 10 for controlling the flow rate of the molten metal is attached to the molten metal discharge port 3 of the pot bottom iron skin 2 of the molten metal pot 1 and its periphery.

  The molten metal flow rate control device 10 includes an upper nozzle 11 that is attached to penetrate the molten metal discharge port 3 formed in the bottom iron shell 2 and the base plate 4 on the lower surface thereof, and an outer periphery of the upper nozzle 11 in the molten metal pan 1. The tuyere 7 to be connected, the fixture 12 attached to the lower side of the base plate 4 and having a hole through which the upper nozzle 11 passes, and the molten metal passage hole 11a of the upper nozzle 11 fixed to the fixture 12 The upper plate 22 having another molten metal passage hole 22a, a lower plate 23 overlapping the upper plate 22, a slide metal frame 13 supporting the lower plate 23, and the molten metal passage hole 23a of the lower plate 23. Supporting the lower nozzle 14 having another molten metal passage hole 14a, the slide metal frame 13, the slide gate plate 21, the lower nozzle 14 and the like. And opening and closing metal frame 15 which is opened and closed when their parts detachable, and a lower plate sliding mechanism 16 for sliding the lower plate 23 in the lateral direction, further comprising other components. The lower end of the lower nozzle 14 is exposed to the outside through a heat insulating cover 5 that covers the molten metal flow rate control device 10 from below.

  The lower plate sliding mechanism 16 has a drive cylinder 19 that slides the slide metal frame 13 laterally via a connecting rod 17 and a bell crank 18 and drives the drive cylinder 19 by a control circuit (not shown). By doing so, the relative positions of the molten metal passage holes 22a and 22b of the lower plate 23 and the upper plate 22 are controlled.

  The upper plate 22 and the lower plate 23 constitute a slide gate plate 21 and are formed on one side of the base bricks 22b and 23b made of alumina carbon, alumina zirconium, etc., as shown in FIGS. 2 (a) and 2 (b). The molten metal passage holes 22a and 23a are integrally formed in the thickness direction on the protrusions 22c and 23c and the base bricks 22b and 23b.

  The base bricks 22b and 23b have a length of about 500 mm, a width of about 200 mm, and a thickness of about 45 mm, for example. The diameter of the molten metal passage holes 22a and 23a is, for example, about 85 mm.

  The surfaces of the upper plate 22 and the lower plate 23 that do not have the protrusions 22c and 23c are sliding surfaces that slide against each other. The lower plate 23 is slid by the lower plate sliding mechanism 16 so The overlapping area of 22a and 23a is adjusted, and it is comprised so that the flow volume of the molten metal which flows through them may be controlled.

  Further, the protrusion 22 c of the upper plate 22 has a shape that fits into a recess formed at the lower end of the upper nozzle 11, and similarly, the protrusion 23 c of the lower plate 23 is formed into a recess formed at the upper end of the lower nozzle 14. It has a shape that fits together. As a result, the upper plate 22 is held at the same position as the upper nozzle 11, and the lower plate 23 moves together with the lower nozzle 14.

  Then, in a state where at least a part of the molten metal passage holes 22a and 23a of the upper plate 22 and the lower plate 23 overlap each other, the high temperature molten metal flowed from the molten metal ladle 1 is the upper nozzle 11 and the slide gate plate 21. The lower nozzle 14 flows through the molten metal passage holes 11a, 22a, 23a, and 14a and is supplied to the lower target position. As the molten metal flow time elapses, the molten metal passage holes 22a and 23a and the periphery of the slide gate plate 21 are damaged by heat.

  The damaged upper plate 22 and lower plate 23 are recycled and reused. For example, the lower plate 23 is regenerated through the steps shown in FIGS. 3A to 3C and becomes a plan view shown in FIG. 3A to 3C show cross sections viewed from the line II in FIG.

  First, as shown in FIG. 3A, the inner wall surface of the molten metal passage hole 23a of the lower plate 23 has a damaged portion 23x caused by the passage of the molten metal.

  Next, as shown in FIG. 3B, a through hole 24 is formed in a region including the projection 23c in the base brick 23b of the lower plate 23 using a drill (not shown) or the like. The through hole 24 has a tapered surface with no step in the thickness direction on the inner wall, and its planar shape is, for example, a circle.

  The small edge 24a of the through hole 24 may be a surface on which the initial protrusion 23c is formed or a surface that is a sliding surface, but is large enough to receive the initial protrusion 23c. . Further, the taper angle θ of the inner surface of the through hole 24 is, for example, larger than 0 ° and not more than 45 °, preferably not more than 20 ° with respect to a line perpendicular to one surface or the other surface of the base brick 23b. If the taper angle θ is larger than 45 °, the distance between the through hole 24 and the outer edge of the base brick 23b is shortened in the short side direction of the base brick 23b, the cross-sectional area of the region is reduced, and the strength of the base brick 23b is increased. Is unfavorable because it decreases. In addition, when the taper angle θ is 20 ° or less, the base brick 23b around the small end 24a of the through hole 24 is unlikely to become brittle.

  In this case, the taper angle θ is an angle of the cut wall of the through hole 24 that appears in a state where the through hole 24 is cut perpendicularly to the upper surface or the lower surface of the base brick 23b so as to pass through the normal line of the tapered surface of a certain part. is there.

  After such a through hole 24 is formed in the base brick 23b, the replacement brick 25 is fitted from the large end 24b side to the small end 24a of the through hole 24 as shown in FIG. 3 (c). The replacement brick 25 includes a main body 25a having the same shape and size as the through-hole 24, and a protrusion 25b that is formed at the narrow end 25c of the replacement brick 25 and protrudes from the small end 24a of the through-hole 24 to the outside. Is done. The protrusion 25b has the same shape and size as the protrusion 23c of the initial lower plate 23, and a molten metal passage hole 23a that penetrates the main body 25a in the thickness direction is formed at the center of the protrusion 25b. Yes. The replacement brick 25 has a shape that is obtained by cutting a conical tip.

  The replacement brick 23b and the inner wall of the through hole 24 are bonded by mortar, and after the mortar has dried, the wide end 25d of the replacement brick 25 protruding from the large end 24b of the through hole 24 is polished using a polishing jig (not shown). Then, the surface of the base brick 25b on the wide-area end 25d side is flattened. Thus, the polished surface becomes a new sliding surface.

  This completes the regeneration process of the lower plate 23, but the upper plate 22 is also regenerated by the same process.

  The slide gate plate 21 regenerated as described above is incorporated in the molten metal flow rate control device 10 shown in FIG. 1 in a state of being stacked as shown in FIG.

  The position of the lower plate 23 of the slide gate plate 21 is adjusted by the lower plate sliding mechanism 16. And the flow volume of the molten metal supplied from the molten metal ladle 1 is adjusted according to the area where the molten metal passage hole 23a of the lower plate 23 and the molten metal passage hole 22a of the upper plate 22 overlap.

  In this case, the molten metal flows through the molten metal passage holes 22a and 23a, so that a load is also applied to the replacement brick 25 in the lower plate 23, but the joint surface between the through hole 24 of the lower plate 23 and the replacement brick 25 is thick. It is a continuous tapered surface with no step in the direction. Accordingly, there is no acute angle portion in the thickness direction on the inner surface of the through hole 24 of the lower plate 23b, and the force applied to the base brick 23b through the replacement brick 25 is almost equal at any position on the inner wall of the through hole 24, and locally. A large pressure is avoided.

  In addition, when the taper angle θ of the through hole 24 is larger than 0 ° and smaller than 45 °, for example, 3 ° or smaller, the base brick 23b has no portion where cracks are likely to occur due to the load on the replacement brick 25. The fitted replacement brick 25 is not displaced in the thickness direction.

  Therefore, the lower plate 23 and the upper plate 22 regenerated under the above conditions are less likely to cause molten metal leakage as in the case of a new one.

  By the way, when the same slide gate plate is regenerated a plurality of times, the through hole is expanded each time. In the through hole 24 according to the present embodiment, as shown in FIG. 6, the inner surface can be smoothed by increasing the taper angle from θ1 to θ2 as the number of times of regeneration increases. Moreover, since there is no step in the through hole 24, it is only necessary to insert a polishing drill or the like from the large end 24b side of the through hole 24 to polish or grind the base brick 23b to increase the taper angle. Is easy.

  On the other hand, in the case of the conventional regeneration method shown in FIGS. 11 to 13, it is necessary to enlarge the through-hole once every time the number of regenerations is increased in order to prevent the processing accuracy and positional deviation of the through-hole. Therefore, it is difficult to increase the number of playback times compared to the present embodiment.

  The planar shape of the through hole 25 is not limited to the circular shape as shown in FIG. 4, but may be a rhombus as shown in FIG. 7 (a). In this case as well, it is shown in FIG. 7 (b). A through-hole 24 having a tapered surface with no step in the thickness direction on the inner peripheral wall as in the cross section is formed in the base bricks 22b and 23b, and the through-hole 24 has a tapered surface matched to the shape on the outer peripheral wall. The replacement brick 25 is fitted. In addition, as a planar shape of the through-hole 24, as shown in FIG.

  Next, a description will be given of experimental results obtained by creating a sample of the slide gate plate 21 of the present embodiment and a sample of the slide gate plate 101 regenerated by the conventional technique shown in FIGS. 11, 12, and 13. In any sample, the planar shapes of the through holes 24 and 104 and the replacement bricks 25 and 105 were diamonds as shown in FIGS. 7 (a) and 7 (b).

  Each of the regenerated slide gate plates 21 and 101 has a total length of 500 mm, a thickness of 45 mm, and a diameter of the molten metal passage hole of 85 mm. Reproduced slide gate plates 21 and 101 were prepared as 20 pairs of upper plates 22 and 102 and lower plates 23 and 103, respectively. In the regenerated slide gate plates 21, 101, the upper and lower plates 22, 23, 102, 103 and the replacement bricks 25, 105 are made of alumina carbon, and mortar is used to connect the replacement bricks 25, 105. Then, after the mortar was dried, the sliding surface side of the upper and lower plates 22, 23, 102, 103 was polished.

  In addition, the slide gate plates 21 and 101 according to the present example and the prior art each had 12 heats for casting before regeneration. Furthermore, the molten metal pot 1 used the thing of the magnitude | size which can accommodate 300 tons of molten metals.

  Then, as shown in Table 1, the recycle slide gate plate disposal standard was determined in advance, and the number of times of reuse of the slide gate plates 21 and 101 was compared. As a result, the results shown in Table 2 were obtained. In addition, the value shown in Table 2 is an average value in the sample of 20 sets of each slide gate plate.

  According to Table 2, it can be seen that the slide gate plate according to the present example is the most in terms of the number of times of use (lifetime) of the regenerated slide gate plate. Further, among the reasons for disposing of the slide gate plate regenerated by the present embodiment, the hole diameter enlargement and the edge melting damage account for 90%, and this is the state that the base bricks of the upper or lower plates 22 and 23 cannot be used. Indicates that it has been used.

  Thus, by forming a through hole having a tapered surface without a step in the thickness direction in the upper or lower plate as in this embodiment, it becomes possible to stably reuse, reducing manufacturing costs and resources. Furthermore, it became clear that there was no trouble in re-use as much as new products.

  By the way, as shown in the cross section of FIG. 8, the tapered surface of the through hole 24 according to the present embodiment described above is a straight line connecting the edge of the large end 24b and the edge of the small end 24a on both side walls of the cross section of the through hole 24. May be curved inside the through hole 24. According to this, the tangent line of the taper surface approaches the vertical surface with respect to the upper surface or the lower surface of the base brick 23b closer to the fore end in the through hole 24, so that the sharpness around the fore end 24a of the through hole 24 becomes smaller. It becomes difficult to chip when the replacement brick 25 is attached.

  In this case, an angle θ formed by a straight line connecting the upper end edge and the lower end edge on both side walls of the through hole 24 shown in the cross section is greater than 0 ° and not more than 45 °, preferably not more than 20 °.

  In the above-described embodiment, the upper plate 22 and the lower plate 23 are regenerated by the same method. However, the upper plate 22 may be regenerated by a conventional method.

1: Molten pot 1
2: Molten metal flow control device 10
11: Upper nozzle 14: Lower nozzle 21: Slide gate plate 22: Upper plate 23: Lower plate 24: Through hole 25: Replacement brick

Claims (1)

A through hole having a continuous tapered surface with no step in the thickness direction in the region including the molten metal passage portion of the base brick of the plate on the inner periphery, the taper angle θ of the inner surface of the through hole is one surface of the base brick Or, it is formed to be larger than 0 ° and 45 ° or less with respect to a line perpendicular to the other surface,
A main body portion having a tapered surface with no step in the thickness direction on the outer periphery and fitted into the through hole, a protrusion extending from a narrow end of the main body portion, and penetrating the protrusion and the main body portion Prepare replacement bricks with molten metal passage holes,
By fitting the replacement brick into the through hole by inserting the protrusion of the replacement brick from the large end of the through hole of the plate and projecting from the small end,
Polishing the wide-area end of the replacement brick fitted in the through-hole,
A method for regenerating a slide gate plate, wherein the taper angle of the tapered surface of the through hole is increased each time the number of times of regeneration increases.

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