JP5556942B2 - Precast block refractory and ladle lay structure using this precast block refractory - Google Patents

Description

  The present invention relates to, for example, a precast block refractory applied to a laying part of a steel ladle and a laying part structure of a steelmaking ladle using the precast block refractory.

  Examples of the precast block refractory include a tuyere block and a hot water block. For example, an amorphous castable refractory is poured around a ladle laying portion.

  For example, the ladle laying part receives and holds high-temperature molten steel such as 1650 to 1750 ° C. and is exposed to severe conditions such as gas bubbling of the received molten steel in some cases. Moreover, when receiving steel from the melting furnace, it is also exposed to highly erodible molten slag flowing out together with the molten steel.

  Therefore, in the ladle laying section, a precast block that is stronger and more resistant to hot shock than an indeterminate castable refractory is applied to the hot water contact area where the molten steel flow falls into the tuyere and ladle. We are constructing.

  That is, as shown in FIG. 6, the ladle laying section is constructed with SN tuyere precast block 1, porous tuyere precast block 2 and precast block 3 per hot water at predetermined positions, The lining of the unshaped castable refractory 4 is applied.

  However, in the case of construction in which an indeterminate castable refractory and a precast block are combined, the precast block may be lifted during use, or may fall when the remaining hot water is drained after casting. In addition, there may be a problem such as a metal insertion due to a joint opening between the precast block and the indeterminate castable refractory.

  Therefore, Patent Document 1 proposes a tuyere block in which an overhanging portion is provided on the outer periphery of the end portion on the side in contact with the iron skin constituting the molten metal container.

  On the other hand, as a hot water block, Patent Document 2 discloses a technique for covering the entire surface of a precast block and surrounding amorphous castable refractories with a joint relaxation sintered layer, and Patent Document 3 discloses a technique using a fired precast block as the precast block. Proposed.

  However, since the technique disclosed in Patent Document 1 is constructed with brick around the tuyere block, it can prevent falling and rising when the remaining hot water is drained, but the brick joints are similar to conventional ones. There may be money. In addition, since the outer peripheral surface of the tuyere block has a straight shape, it is difficult to effectively suppress the bare metal insertion even at the outer peripheral part of the tuyere block.

  On the other hand, in the case of the technique proposed in Patent Document 2, the joint between the hot water block and the indeterminate castable refractory is covered with a joint relaxation sintered layer. Can be prevented. However, when the joint relaxation sintered layer is melted or cracked, it is difficult to expect effective suppression of the ingot.

  Moreover, in the case of the block per baking hot water proposed by patent document 3, since the outer periphery shape is the same straight as the past, it is difficult to effectively prevent the fall, floating, and metal pouring when the remaining hot water is discharged. .

  Moreover, the hot water block is heavy and requires a hand during construction. However, the part from which the hand is removed may be damaged due to an impact during receiving steel.

JP-A-10-102126 JP-A-2-274371 JP-A-6-71422

  The problem to be solved by the present invention is that, in the case of the prior art, it is difficult to effectively suppress the metal insert between the precast block refractory and the indeterminate castable refractory. In addition, in the case of a block against hot water, a suspension hand is required at the time of construction. Therefore, the part where the suspension is removed may be damaged due to an impact in the steel receiving part. It is a point that there is also a case.

  The present invention effectively suppresses ingots between a precast block refractory and an indeterminate castable refractory, and in the case of a hot water block, it eliminates the need for a hanging hand during construction and In order to effectively prevent floating during use and dropping when draining remaining hot water, the following configuration was adopted.

The present invention is a precast block refractory used as hot water when constructing a ladle for a steel ladle using an indeterminate castable refractory and a precast block refractory,
The retracted width from the outer peripheral surface is 50 mm or more and 100 mm or less and the height is 50 mm or more in the entire outer peripheral surface of the end portion of the precast block refractory that is in contact with the permanent brick constituting the laying portion. The most important feature is that a concave portion of 100 mm or less is formed and the outer peripheral surface portion excluding the concave portion is formed at an angle of 70 ° to 85 ° with respect to the bottom surface of the precast block refractory. Yes.

The present invention also provides:
A ladle structure for a steel ladle in which an amorphous castable refractory is poured around a precast block refractory,
As a tuyere block, while using a precast block refractory formed with a convex portion in the entire outer peripheral surface of the end portion on the side in contact with the iron skin constituting the laying portion,
The main feature is to use the above-mentioned precast block refractory as a hot water block.

In the ladle structure of the ladle for steel making of the present invention,
The precast block refractory used as the tuyere block, the convex part formed in the entire outer peripheral surface of the end part on the side in contact with the iron skin constituting the laying part,
It is desirable that the overhang width from the outer peripheral surface is 50 mm or more and 100 mm or less and the height is 50 mm or more and 100 mm or less.

  Moreover, the part except the said convex part of the outer peripheral part of the precast block refractory used as the said tuyere block may form an angle of 70 ° or more and 85 ° or less with respect to the bottom surface of the precast block refractory. desirable.

  In the present invention, since the precast block refractory used as hot water perforation has a concave portion in the entire outer peripheral surface of the end portion on the side in contact with the perm brick constituting the laying portion of the steelmaking ladle, the castable castable and It is possible to effectively suppress the ingot from the boundary portion. Moreover, the work time at the time of construction can be shortened. Furthermore, it is possible to prevent floating during use and dropping when the remaining hot water is discharged.

It is sectional drawing of a tuyere block used for the laying part structure of this invention. It is sectional drawing of the hot water block of this invention. It is sectional drawing which shows the spread part structure of this invention. It is a comparison figure of the number of bullion occurrences. It is a comparison figure of the working time at the time of setting a block per hot water. It is a top view of a ladle laying part. It is sectional drawing of the conventional tuyere block. It is sectional drawing of the conventional hot water block.

  The present invention effectively suppresses the ingot between the precast block refractory and the irregular castable refractory, eliminates the need for a hot water block block during construction, and lifts and remains during use of the hot water block. The purpose of preventing falling when the hot water is drained is realized by changing the shape of the precast block refractory.

  The inventor conducted various studies on the shape and laying structure of the precast block refractory, and as a result of repeated tests, the following knowledge was obtained.

(About tuyere block)
Conventionally, when a laying part such as a ladle was laid with a brick, a straight brick was used as the laying brick. Also, the tuyere block used a straight brick with a rectangular shape in plan view, but the use of an indeterminate castable refractory has led to the use of a tuyere block with a plan view circular shape.

  However, by using the tuyere block 11 having a circular shape in plan view, as shown in FIG. 7, the joint 13 between the tuyere block 11 and the indeterminate castable refractory 12 passes to the iron skin 14 and becomes a through joint. As a result, a bullion will be generated. In FIG. 7, 15 indicates a large-floor castable refractory, and 16 indicates a permanent brick.

  Therefore, as shown in FIG. 1, the protrusions 22 are provided on the entire outer peripheral surface of the end portion of the tuyere block 21 on the side in contact with the iron skin 14 that constitutes the laying portion (hereinafter referred to as the iron side edge). It was found that the intrusion of the metal can be stopped at the position of the permanent brick 16 or the convex portion 22 by forming.

  If the tuyere block 21 is inclined at an angle of 70 to 85 ° with respect to the bottom surface of the tuyere block 21, the length of the joint 13 is increased and the contact area with the amorphous castable refractory 12 is increased. As a result, the vertical force of the molten steel is relaxed and the invasion of the metal is suppressed. In addition, since the indeterminate castable refractory 12 covers the tuyere block 21, it is possible to prevent floating during use and dropping at the time of discharging the remaining hot water after completion of receiving steel.

  Further, the tuyere block 21 can suppress the occurrence of cracks in the convex portion 22 if the protruding width and height of the convex portion 22 from the outer peripheral surface are 50 mm or more and 100 mm or less, respectively. It is possible to prevent floating and falling when discharging remaining hot water.

(About the block per hot water)
Since the boundary portion 32 between the conventional hot water block 31 and the indeterminate castable refractory 12 is vertical as shown in FIG. 8, intrusion of the metal is likely to occur during operation. Therefore, there is a problem that the hot water hitting block 31 is lifted during use, and the hot water hitting block 31 is dropped when the remaining hot water is discharged after the steel receiving is finished.

  In addition, the hot water block 31 is heavy, so it is set with a hand 33 during construction. After the work, the hand is removed with the hand 33 removed. There was a problem that the damaged part was damaged.

  Therefore, as shown in FIG. 2, the retracted width and height from the outer peripheral surface of the block 41 of hot water is in the entire outer peripheral surface of the end portion on the side in contact with the permanent brick 16 constituting the laying portion such as a ladle, By forming recesses 42 of 50 mm or more and 100 mm or less, and forming the outer peripheral surface portion excluding the recesses 42 at an angle of 70 ° or more and 85 ° or less with respect to the bottom surface of the hot water block 41. It has been found that the joint length is increased, the intrusion of the bullion is suppressed, the bullion does not proceed to the permanent brick 16 and stops at the position of the recess 42.

  Further, it has been found that the hot water block 41 is covered with the irregular castable refractory 12, and the hot water block 41 does not fall or rise. Further, since the recess 42 is provided on the floor surface and the suspension is eliminated, the block damage of the portion where the suspension is removed is eliminated, and the slinging wire is not sandwiched between the permanent brick 16 and the hot water block 41 during construction. It is only necessary to hang a sling wire on the recess 42, and the working time can be shortened.

The present invention has been made based on the above findings,
In the case of a precast block refractory used as a tuyere when laying a ladle for a steelmaking ladle using an indeterminate castable refractory and a precast block refractory, a convex portion is provided on the entire outer peripheral surface of the iron skin side end. The most important feature is the formation.

  In this case, the protrusion formed on the entire outer peripheral surface of the iron skin side end of the tuyere block has a protruding width from the outer peripheral surface of 50 mm or more and 100 mm or less and a height of 50 mm or more and 100 mm. The following is desirable.

  In addition, it is desirable that a portion of the outer peripheral portion of the tuyere block excluding the convex portion has an angle of 70 ° to 85 ° with respect to the bottom surface of the tuyere block.

  In the present invention, the reason why the overhang width and height from the outer peripheral surface of the convex portion of the tuyere block are preferably 50 to 100 mm, respectively, is to prevent lifting during use and prevention of falling when discharging remaining hot water when it is less than 50 mm. This is because the effect of. On the other hand, if it is larger than 100 mm, stress is applied to the base of the convex portion, causing cracks.

  In addition, in the present invention, the reason why it is desirable that the portion of the outer peripheral portion of the tuyere block excluding the convex portion is set to an angle of 70 ° or more and 85 ° or less with respect to the bottom surface of the tuyere block is as follows. is there.

  When the angle is larger than 85 °, the vertical force of the molten steel is increased and the intrusion of the metal becomes easy to occur, and it is easy to fall when the remaining hot water is discharged, and stress is applied to the base of the convex portion to the convex portion. This is because cracks may occur and fall. On the other hand, when the angle is less than 70 °, the thickness of the surrounding amorphous castable refractory is reduced on the operating surface side, and the wear of the amorphous castable refractory progresses from the operating surface side.

In addition, in the case of block refractories used as hot water per unit when constructing the laying part of a ladle for steel making using irregular castable refractories and precast block refractories,
A recess having a retraction width of 50 mm or more and 100 mm or less and a height of 50 mm or more and 100 mm or less from the outer peripheral surface over the entire outer peripheral surface of the end portion in contact with the permanent brick 16 constituting the laying portion. The main feature is that the outer peripheral surface portion excluding the recess is formed at an angle of 70 ° to 85 ° with respect to the bottom surface of the precast block refractory.

  In the present invention, the recesses formed in the entire outer peripheral surface of the end portion of the hot water contact block on the side in contact with the perm brick have a retraction width and height from the outer peripheral surface of 50 mm or more and 100 mm or less, respectively. Depending on the reason.

  When the retracted width and height are less than 50 mm, the thickness of the amorphous castable refractory entering the recess is reduced, and the strength of the amorphous castable refractory is reduced. Because it becomes. On the other hand, when the retraction width and height exceed 100 mm, the strength in the longitudinal direction is lowered, and the effectiveness of the hot water block is lowered.

  In the present invention, the outer peripheral surface portion excluding the concave portion is formed at an angle of 70 ° to 85 ° with respect to the bottom surface of the hot water block for the following reason. That is, when the angle is less than 70 °, the boundary between the hot water contact block on the operating surface side and the irregular castable refractory becomes an acute angle, and the wear of the irregular castable refractory is accelerated. On the other hand, if the angle exceeds 85 °, the outer peripheral surface tends to be vertical and a vertical force is applied to the joint, so that the entry of the metal into the joint is likely to occur. Moreover, it is easy to occur during use and to drop when the remaining hot water is discharged.

  When constructing the laying part of the ladle for steel making, as shown in FIG. 3, if the tuyere block 21 and the hot water block 41 are used as described above, the bullion insert from the boundary with the irregular castable refractory 12 is used. Can be effectively suppressed. Moreover, the work time at the time of setting the block 41 per hot water can be shortened. Furthermore, it is possible to prevent the hot water block 41 from being lifted during use and falling when the remaining hot water is discharged. This is the laying part structure of the ladle for steel making according to the present invention.

  By the way, when using the tuyere block used in the laying part structure of the present invention shown in FIG. 1 and the hot water contact block of the present invention shown in FIG. 2 and using a VOD ladle constructed as shown in FIG. 4 and 5 show the results of investigating the number of bullion feeds and the work time required to set the blocks per hot water.

  The molten steel delivered to the VOD ladle was Ni-based and Cr-based stainless steel having a temperature of 1700 to 1750 ° C., and was discharged 27 times by 75 tons per heat. As a comparison, the results when using a VOD ladle constructed using the conventional tuyere block shown in FIG. 7 and the hot water block shown in FIG. 8 are also shown in FIGS.

  In the present invention, there are no metal bars for both the tuyere block and the hot water block (see FIG. 4). In addition, the work time for setting a block per hot water, which conventionally took 30 minutes, can be performed in 5 minutes (see FIG. 5).

  The present invention is not limited to the above example, and it goes without saying that the embodiments may be changed as appropriate within the scope of the technical idea described in each claim.

  The present invention as described above can be applied not only to a ladle but also to a molten metal container such as a converter.

12 Indeterminate castable refractory 16 Perm brick 21 Tuyere block 22 Convex part 41 Hot water block 42 Concave part

Claims (4)

A precast block refractory used as hot water when constructing a ladle for a steel ladle using an indeterminate castable refractory and a precast block refractory,
The retracted width from the outer peripheral surface is 50 mm or more and 100 mm or less and the height is 50 mm or more in the entire outer peripheral surface of the end portion of the precast block refractory that is in contact with the permanent brick constituting the laying portion. A precast block having a recess of 100 mm or less and the outer peripheral surface portion excluding the recess formed at an angle of 70 ° to 85 ° with respect to the bottom surface of the precast block refractory Refractory. A ladle structure for a steel ladle in which an amorphous castable refractory is poured around a precast block refractory,
As a tuyere block, while using a precast block refractory formed with a convex portion in the entire outer peripheral surface of the end portion on the side in contact with the iron skin constituting the laying portion,
A ladle structure for a ladle for steel making, wherein the precast block refractory according to claim 1 is used as a hot water block. The precast block refractory used as the tuyere block, the convex part formed in the entire outer peripheral surface of the end part on the side in contact with the iron skin constituting the laying part,
The ladle structure for a steel ladle according to claim 2, wherein the overhang width from the outer peripheral surface is 50 mm or more and 100 mm or less and the height is 50 mm or more and 100 mm or less. The part excluding the convex part of the outer peripheral part of the precast block refractory used as the tuyere block,
The ladle laying structure for a steel ladle according to claim 2 or 3, wherein the ladle has an angle of 70 ° to 85 ° with respect to the bottom surface of the precast block refractory.

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