JP2008101244A - Lance pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lance pipe capable of suppressing the bending of a core bar caused by the buoyancy of molten metal and the rectilinear propagation of cracks in a refractory layer caused by the bending. <P>SOLUTION: The lance pipe 1 comprises: a tubular core bar 10 having a circulation path 11 of allowing at least either a gas or a molten metal treatment agent to be circulated; a plurality of bar-shaped reinforcing ribs 2 provided along the shaft length direction of the outer circumferential face of the core bar 10; annular reinforcing rings 3 circumscribed to the plurality of reinforcing ribs 2; and refractory layers 4 for covering the outer circumferential face of the core bar 10, the reinforcing ribs 2, and the reinforcing rings 3. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a lance pipe, and more particularly to a lance pipe that is immersed in a molten metal and supplies a gas or a molten metal treating agent into the molten metal.

  Lance pipes are used for agitation of molten metal such as molten iron and molten steel, removal of non-metallic components such as dephosphorization, decarbonization, desiliconization and desulfurization, component adjustment, temperature control, etc. This is a long pipe that blows gas and molten metal treatment agent into the molten metal. This lance pipe is mainly composed of a metal pipe (core metal) such as steel and a refractory layer provided so as to cover the outer peripheral surface of the core metal. And when immersed in the molten metal, the lance pipe having a specific gravity smaller than that of the molten metal receives buoyancy, and bending stress acts on it, so that the core metal heated and softened by the extremely high temperature molten metal of over a few hundred degrees Celsius is bent. Sometimes.

  Therefore, conventionally, as illustrated in FIGS. 4A and 4B, rod-shaped reinforcing ribs 102 are provided on the outer peripheral surface of the core metal 110 along the axial length direction, and the outer peripheral surface of the core metal 110 and the reinforcing ribs 102 are provided. A lance pipe 100 provided with a refractory layer 104 so as to cover it is used. Such a reinforcing rib 102 increases the rigidity of the cored bar 110 and makes it difficult for deformation due to bending stress to occur.

  The above prior art is publicly implemented, and the applicant has not found a document describing this prior art at the time of filing this application.

  However, even if the reinforcing ribs as described above are provided, the core metal cannot be sufficiently bent, and the refractory layer may be cracked or peeled off due to the deformation of the core metal. In addition, once a crack occurs, the crack is likely to extend linearly along the reinforcing rib. Furthermore, there has been a problem that the core metal directly in contact with the molten metal is damaged by cracking or peeling of the refractory layer.

  Therefore, in view of the above circumstances, the present invention provides a lance pipe that can suppress the bending of the core metal due to the buoyancy of the molten metal and the linear extension of cracks generated in the refractory layer accompanying this. It is to be an issue.

  In order to solve the above-mentioned problem, the lance pipe according to the present invention is a lance pipe immersed in a molten metal, and has a tubular metal core having a flow path for flowing at least one of gas and a molten metal treatment agent. A plurality of rod-shaped reinforcing ribs provided on the outer peripheral surface of the core metal along the axial length direction, an annular reinforcing ring circumscribing the plurality of the reinforcing ribs, an outer peripheral surface of the core metal, the reinforcing rib, and And a refractory layer covering the reinforcing ring.

Examples of the “melting agent” include powders such as CaO, FeO, Na ₂ CO ₃ , and CaF ₂ and various additives for adjusting components. In addition, the “gas” includes an oxygen gas for performing an oxidation reaction in the molten metal, an inert gas such as argon blown as a medium for conveying the molten metal treatment agent, or for stirring or temperature control of the molten metal. And nitrogen gas.

  The “core metal” is a tubular member made of a metal such as steel or alloy steel. For example, the cross section can be formed in a substantially circular or elliptical shape. The material and dimensions can be set as appropriate depending on the amount of molten metal to be processed, the processing temperature, the type and flow rate of the melt processing agent to be circulated, and the like.

  The “reinforcing rib” is a rod-like member made of a metal such as steel or alloy steel, and can be formed to have a substantially circular, elliptical, rectangular, or polygonal cross section, for example. Moreover, it may be solid or hollow (tubular), and if it is solid, it can have higher rigidity, and if it is hollow, the weight of the lance pipe can be reduced. In addition, a plurality of “reinforcing ribs” are provided on the outer peripheral surface of one cored bar along the axial length direction. The material and dimensions of the “reinforcing ribs” can be appropriately set according to the processing temperature of the target molten metal, the dimensions of the core metal, and the like. Moreover, as long as it is provided along the axial length direction of a metal core, it may be provided over the full length of a metal core, or may be provided partially.

  The “reinforcing ring” is an annular member made of a metal such as steel or alloy steel, and is arranged so as to circumscribe a plurality of reinforcing ribs along the inner periphery thereof. Further, the cross section of the “reinforcing ring” may be, for example, a substantially circular shape, an elliptical shape, a rectangular shape, or a polygonal shape, and may be solid or hollow. For example, a plurality of reinforcing rings can be provided at predetermined intervals along the axial direction of the cored bar. In this case, even if it is provided over the entire length of the cored bar, it is partially provided. May be used. In addition, the material which comprises a metal core, a reinforcement rib, and a reinforcement ring may be the same, or may differ.

  The type of the refractory material constituting the “refractory layer” is not particularly limited. For example, the alumina-silica-based, high-alumina-based, and alumina-chromium-based refractory materials having excellent spalling resistance, and excellent thermal shock resistance and corrosion resistance. An alumina-magnesia refractory material can be used. Further, the refractory layer formed on one lance pipe may be composed of a single type of refractory material, or may be partially provided with different types of refractory material. . Furthermore, the refractory layer is a castable refractory layer that has been solidified and dried from the castable refractory material mud, or a regular refractory layer formed through a pressure forming process. It may be a refractory layer.

  With the above configuration, when the lance pipe is immersed in the molten metal and bending stress acts on the cored bar due to the buoyancy received from the molten metal, it becomes the reinforcing rib on which the compressive stress acts on the inner part of the bending, and the outer side of the bending Reinforcing ribs on which tensile stress acts are connected to each other by a reinforcing ring. Thereby, the force which cancels the compressive stress and tensile stress by bending acts. In addition, in the conventional lance pipe, bending in a certain direction must be resisted by bending ribs mainly inside or outside the bending, whereas in the present invention, The plurality of reinforcing ribs connected to each other by the reinforcing ring cooperate to form a structure that resists bending stress. Therefore, according to the present invention, the core bar is hardly deformed by bending stress. In addition, since the rigidity against bending is higher than the conventional product (see FIG. 4), even if the core metal bends and cracks occur in the refractory layer, further deformation is suppressed, Linear extension along the axial direction is suppressed.

  In addition, the connection between the core metal and the refractory layer is strengthened by filling the periphery of the connecting portion between the reinforcing rib and the reinforcing ring and the gap between the outer peripheral surface of the core metal and the reinforcing ring with the refractory. The That is, the reinforcing ring not only connects the reinforcing ribs but also acts as an anchor member that holds the refractory layer on the cored bar. In addition, the reinforcing ring has a structure in which a refractory layer is interposed between the outer peripheral surface of the core metal and not in contact with the outer peripheral surface of the core metal except for the connecting portion with the reinforcing rib. Thereby, even if the core metal heated by the high-temperature molten metal expands, the reinforcing ring does not easily follow the expansion, and the bonded state of the core metal and the refractory layer can be well maintained.

  Further, the lance pipe according to the present invention can be "the cross section of the reinforcing rib and the reinforcing ring is formed in a substantially circular shape or a substantially rectangular shape".

  Therefore, according to the present invention, the reinforcing rib and the reinforcing ring can be configured by using a general-purpose material by making the reinforcing rib and the reinforcing ring into a rod shape having a substantially circular or substantially rectangular cross section. However, it is possible to manufacture the lance pipe at a lower cost by using an easy material. Furthermore, since the shapes of the reinforcing rib and the reinforcing ring are not complicated, the attachment to the outer surface of the cored bar and the operation of connecting the reinforcing rib and the reinforcing ring become simpler.

  Furthermore, the lance pipe according to the present invention may be “the reinforcing ring is provided at least in a dipping portion immersed in the molten metal”.

  The “immersion part” is a part of the lance pipe that is immersed in the molten metal, and can be, for example, a part corresponding to 1/2 to 2/3 of the total length.

  Therefore, according to the present invention, since the reinforcing rib is connected by the reinforcing ring at the portion where the lance pipe receives buoyancy from the molten metal, the bending of the cored bar due to the buoyancy can be more reliably suppressed.

  As described above, as an effect of the present invention, it is possible to provide a lance pipe that can suppress the bending of the core metal due to the buoyancy of the molten metal and the linear extension of the crack generated in the refractory layer accompanying this. Can do.

  Hereinafter, a lance pipe which is the best embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 (a) is a longitudinal sectional view of the lance pipe of the present embodiment, FIG. 1 (b) is a sectional view taken along line AA of FIG. 1 (a), and FIG. 1 (c) is a reinforcing rib. And FIG. 2A is a longitudinal sectional view of a lance pipe of a control example, and FIG. 2B is a sectional view taken along line BB in FIG. 2A. FIG. 2 (c) is a side view of the cored bar provided with the reinforcing rib, and FIG. 3 is an explanatory view showing a usage state of the lance pipe. 1 to 3 are schematic views and do not accurately represent the shape and dimensional ratio of each part of the lance pipe.

  As shown in FIG. 1, the lance pipe 1 of the present embodiment includes a tubular cored bar 10 having a flow path 11 through which at least one of a gas and a molten metal treating agent is circulated, and an axial length on the outer peripheral surface of the cored bar 10. A plurality of rod-shaped reinforcing ribs 2 provided along the direction, an annular reinforcing ring 3 circumscribing the plurality of reinforcing ribs 2, a refractory covering the outer peripheral surface of the cored bar 10, the reinforcing rib 2, and the reinforcing ring 3. Layer 4.

  More specifically, the metal core 10 is a heat-resistant metal such as steel or alloy steel, and is formed in a long tubular shape having a substantially circular cross section. It extends in the axial direction at the center of the tube. And as shown in FIG. 3, the inlet 11b connected with the supply apparatus (not shown) which supplies a molten metal processing agent to the upper end of the distribution path 11 is provided, and the lower end of the distribution path 11 is at the lower end. A discharge port 11 c for discharging the molten metal treatment agent is provided in the molten metal 22. In addition, although the figure illustrates the case where the distribution path 11 opens to the lower end of the lance pipe 1 to form the discharge port 11c, the present invention is not limited to this, and the lower end of the distribution path 11 is the closed end, and the distribution path A plurality of outlets may be provided so as to branch from 11.

  The reinforcing rib 2 is made of a solid rod-shaped metal material having a substantially circular cross section, and the four reinforcing ribs 2 are arranged with respect to the axis of the cored bar 10 as shown in the cross section in FIG. They are arranged radially at substantially equal angular intervals and welded to the outer peripheral surface of the cored bar 10. The reinforcing ring 3 is made of a solid metal material having a substantially rectangular cross section, and is welded to the reinforcing rib 2 so that the inner peripheral surface thereof circumscribes the reinforcing rib 2. In addition, as shown in FIGS. 1A and 1C, a plurality of reinforcing rings 3 are provided at predetermined intervals along the axial length direction of the core metal 10. In addition, in this embodiment, although the space | interval of the reinforcement ring 3 is about 150 mm, it is not limited to this. Moreover, the reinforcing rib 2 and the reinforcing ring 3 of this embodiment are provided on the cored bar 10 of the immersion part 6 (see FIG. 3) immersed in the molten metal 22 as described later.

  The refractory layer 4 of the present embodiment includes a core metal 10 provided with reinforcing ribs 2 and a reinforcing ring 3 made of a mixture of castable refractory material mixed with water and adjusting agents such as a binder, a curing agent, and a dispersing agent. It is a castable refractory layer formed by pouring into a mold placed in the center under vibration, solidifying, and drying. In this embodiment, an alumina-silica refractory material having the following composition is used as the castable refractory material. In addition, as mentioned above, the kind of refractory material which comprises the refractory material layer 4 is not limited to this, It can select suitably based on the characteristic requested | required. 1 and 3, the case where the refractory layer 4 is formed in a substantially cylindrical shape concentric with the core metal 10 is illustrated, but the present invention is not limited to this, and the diameter of the refractory layer 4 is not limited thereto. The thickness in the direction may be partially different. For example, the refractory layer 4 in the immersion part 6 can be thickened in consideration of the amount of melt loss to the molten metal 22.

<Composition of castable refractory material>
Alumina 90 parts by weight Silica 7 parts by weight Others 3 parts by weight

  As shown in FIG. 3, the lance pipe 1 is inserted into the molten metal 22 accommodated in the ladle 21 in a substantially vertical direction. Then, when the molten metal treatment agent is introduced into the introduction port 11b with the lance pipe 1 immersed in the molten metal 22, the molten metal treatment agent is discharged into the molten metal 22 through the flow path 11 and the discharge port 11c. . At this time, the portion corresponding to the length L in which the lance pipe 1 is immersed in the molten metal 22 is the immersion portion 6, and in this embodiment, the length of about ½ of the entire length is the immersion portion 6. A reinforcing rib 2 and a reinforcing ring 3 are provided on the core metal 10.

  Next, the molten metal process is actually performed using the lance pipe 1 having the above-described configuration, and the results of bending and cracking in comparison with the control example will be described. Here, as shown in FIG. 2, the lance pipe 50 of the control example has all the dimensions and the composition of the refractory material constituting the refractory material layer 4 except that the reinforcing ring 3 is not provided. It is the same composition as. In FIG. 2, the same components as those of the lance pipe 1 of the present embodiment are denoted by the same reference numerals.

As described above with reference to FIG. 3, the lance pipe 1 of the present embodiment and the lance pipe 50 of the control example are each immersed in molten steel (molten metal 22) accommodated in the ladle 21, and slag is formed on the liquid surface of the molten metal 22. In a state of floating, argon gas was blown under the following processing conditions to perform LF (Laddle Furnace) processing.
<Processing conditions>
C / S = 3
Molten steel temperature 1650 ° C
Argon gas pressure: 0.49 MPa, flow rate: 500 l / min
Processing time 45min

  As a result, in the lance pipe 1 of the present embodiment, the bending of the lance pipe 1 and the occurrence of cracks in the refractory layer 4 were not observed even after the treatment under the above conditions was repeated 10 times. In contrast, in the lance pipe 50 of the control example, when the treatment was repeated five times, a crack occurred in the refractory layer 4, and further, the crack extended linearly along the axial length direction, so the treatment was stopped. .

  As described above, according to the lance pipe 1 of the present embodiment, when bending stress is applied to the cored bar 10 by the buoyancy received from the molten metal 22, the reinforcing rib 2 in which compressive stress is applied to the inner portion of the bending. And the reinforcing rib 2 on which the tensile stress acts on the outer part of the bend are connected to each other by the reinforcing ring 3, so that the action of canceling out the compressive stress and the tensile stress works, and the reinforcing ring The plurality of reinforcing ribs 2 connected to each other by 3 cooperate to resist bending stress, so that the cored bar 10 is difficult to deform. Further, even if the core metal 10 is bent and a crack occurs in the refractory layer 4, further deformation is suppressed, so that the crack is suppressed from extending linearly along the axial length direction. .

  In addition, the refractory layer 4 can be firmly held on the outer peripheral surface of the cored bar 10 by the reinforcing ring 3 that also serves as an anchor member.

  Further, the reinforcing rib 2 and the reinforcing ring 3 made of solid metal have high rigidity, and the cored bar 10 is more difficult to bend. In addition, the reinforcing rib 2 and the reinforcing ring 3 of the present embodiment have a substantially circular shape and a substantially rectangular cross section, respectively, and can be configured by using a general-purpose metal material. Can be manufactured. In addition, since the shapes of the reinforcing rib 2 and the reinforcing ring 3 are not complicated, the attachment of the reinforcing rib 2 to the cored bar 10 and the operation of connecting the reinforcing rib 2 and the reinforcing ring 3 are simple.

  Further, if a large number of reinforcing ribs 2 are provided, the overall configuration becomes complicated, increasing the labor and cost of manufacturing, and when the number of reinforcing ribs 2 is small, the mounting state of the reinforcing ring 3 is not satisfactory. In addition to being stable, the cored bar 10 is easily bent when bending stress acts in a direction in which the reinforcing rib 2 is not disposed. On the other hand, since the four reinforcing ribs 2 of this embodiment are provided radially at substantially equal angular intervals with respect to the axis of the core metal 10, the number of the reinforcing ribs 2 is suppressed and the reinforcing ribs 2 are suppressed. The mounting state of the reinforcing ring 3 can be stabilized, and the cored bar 10 is hardly deformed regardless of the bending stress acting in any direction. In addition, the above-mentioned effect can be produced by providing at least three reinforcing ribs.

  In addition, since the reinforcing ring 3 connects the reinforcing ribs 2 with each other at the immersion part 6, the bending of the cored bar 10 due to the buoyancy received from the molten metal 22 can be more reliably suppressed.

  The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements can be made without departing from the scope of the present invention as described below. And design changes are possible.

  For example, in the present embodiment, the case where the lance pipe is inserted in a substantially vertical direction with respect to the molten metal accommodated in the ladle is illustrated, but the present invention is not limited to this, and the molten metal is inserted obliquely from above. The present invention can also be applied to a lance pipe to be used. Moreover, in addition to the structure of this embodiment, it can also be set as the structure further equipped with the well-known stud (anchor member) of V type and Y type for hold | maintaining a refractory material layer to a metal core.

(A) is a longitudinal cross-sectional view of the lance pipe of the present embodiment, (b) is a cross-sectional view taken along the line AA of (a), and (c) is a side surface of a cored bar provided with reinforcing ribs and reinforcing rings. FIG. (A) is a longitudinal cross-sectional view of a lance pipe of a control example, (b) is a BB cross-sectional view of (a), and (c) is a side view of a core bar provided with reinforcing ribs. It is explanatory drawing which shows the use condition of a lance pipe. It is a cross-sectional view of a conventional lance pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lance pipe 2 Reinforcement rib 3 Reinforcement ring 4 Refractory layer 6 Immersion part 10 Metal core 11 Distribution channel 11b Inlet 11c Discharge port 22 Molten metal

Claims (3)

A lance pipe immersed in the molten metal,
A tubular cored bar having a flow path for flowing at least one of gas and molten metal treatment agent;
A plurality of rod-shaped reinforcing ribs provided on the outer peripheral surface of the cored bar along the axial length direction;
An annular reinforcing ring circumscribing the plurality of reinforcing ribs;
A lance pipe comprising an outer peripheral surface of the core metal, the reinforcing rib, and a refractory layer covering the reinforcing ring.   The lance pipe according to claim 1, wherein each of the reinforcing rib and the reinforcing ring has a substantially circular or substantially rectangular cross section.   The lance pipe according to claim 1, wherein the reinforcing ring is provided at least in an immersion part immersed in the molten metal.

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