JP2007111744A - Induction heating tundish and repair method thereof - Google Patents

Abstract

An induction heating tundish that reduces the amount of deposits adhering to the molten steel contact surface of a hollow refractory compared to the prior art and that allows easy removal of the deposits and enables stable casting over a long period of time. The repair method is provided.
SOLUTION: A hollow refractory material 12 forming a molten steel flow path 11 is provided at a bottom portion 13 and is heated by the molten steel flow path 11 with a receiving steel part 16 that receives molten steel 15 poured by a weir 14 having induction heating means. In the induction heating type tundish 10 in which the molten steel discharge part 19 for flowing the molten steel 17 to the mold 18 is formed, the hollow refractory 12 has CaO component-containing refractory materials 23 and 24 on the molten steel contact surface 22 side, and this CaO component A low melting point compound is formed with the Al ₂ O ₃ component in the molten steel 15 to suppress adhesion of deposits on the molten steel contact surface 22. In this repair method, after casting the molten steel 15 through the molten steel flow path 11, water is applied to the refractory materials 23 and 24 to remove deposits on the molten steel contact surface 22.
[Selection] Figure 1

Description

The present invention relates to an induction heating tundish used for continuous casting of molten steel and a repair method thereof.

Conventionally, as shown in FIG. 4, after the molten steel in the ladle 80 is supplied to the tundish 81, the molten steel is solidified while being continuously discharged into the mold 82, thereby producing a slab 83.
This tundish 81 is provided with a steel receiving portion 87 for receiving molten steel poured from a ladle 80 by a weir 86 provided with a cylindrical hollow refractory 85 forming a molten steel passage 84 and provided with induction heating means. A molten steel discharge portion 88 is formed for flowing the molten steel that flows while being induction-heated from the steel receiving portion 87 through the molten steel flow path 84 to the mold 82.
By providing such a weir 86, it is possible to efficiently heat the molten steel flowing in the molten steel flow path 84 without transmitting the molten metal level fluctuation generated in the steel receiving portion 87 to the molten steel discharge portion 88, and the necessary temperature of the molten steel. The effect of ascending and removing inclusions in the molten steel can be promoted by the upward flow formed in the molten steel discharge portion 88.

However, the molten steel contact surface 89 of the hollow refractory 85 of the tundish 81, for example, (also referred to as obstruction) Al ₂ O ₃ inclusions or deposits such as bullion 90 is attached or deposited easily, molten steel There is a possibility that the flow path 84 becomes narrow and the flow of molten steel becomes worse, and stable casting cannot be performed.
Thus, for example, Patent Document 1 discloses a repairing method in which a blockage adhering to a molten steel contact surface of a hollow refractory is melted and removed with a high-temperature combustion frame and then reused without replacing the hollow refractory. Yes.
In Patent Document 2, the inner diameter of the hollow refractory is set so that the Reynolds number (Re) of the molten steel flow in the hollow refractory is 2 × 10 ⁵ or more, and the outer periphery of the molten steel inlet of the hollow refractory A method of blowing an inert gas from a part is disclosed.

JP-A-8-300112 JP-A-8-1289

However, since the method of Patent Document 1 uses a high-temperature combustion flame to remove the obstruction, the obstruction cannot be sufficiently cut away, and the hollow refractory is also oxidized and melted when the obstruction is melted. For example, there is a problem that causes a decrease in the lifetime of the hollow refractory or a trouble of leakage of molten steel.
Further, in the method of Patent Document 2, since the inert gas is blown only from the outer peripheral portion of the molten steel inlet, the blockage of the blockage occurrence region of the molten steel channel cannot be suppressed and further prevented. Casting is stopped due to blockage of the path, or the molten steel cannot be heated due to the occurrence of pinch force. In this way, not being able to heat the molten steel, not only does the temperature drop of the molten steel occur, but the thermal convection of the molten steel is weakened, and the floating effect of inclusions is impaired, so the effect of improving the cleanliness cannot be obtained, There is a problem that deteriorates the product quality.

The present invention has been made in view of such circumstances, and reduces the amount of deposits adhering to the molten steel contact surface of the hollow refractory compared to the prior art, and is easy to remove the deposits, and stable casting over a long period of time. It is an object of the present invention to provide an induction heating tundish and a repair method thereof.

The induction heating type tundish according to the first aspect of the present invention has a weir having a hollow refractory forming a molten steel flow path provided at the bottom and provided with induction heating means. In an induction heating type tundish in which a steel receiving part for receiving molten steel and a molten steel discharge part for flowing molten steel flowing into the mold while being induction heated from the steel receiving part through the molten steel flow path are formed,
The molten refractory has a refractory material containing a CaO component in part or all of the molten steel contact surface side of the hollow refractory, and in use, in the molten steel flowing through the molten steel flow path with the CaO component in the refractory material. A low-melting-point compound is formed with the Al ₂ O ₃ component, and adhesion of deposits to the molten steel contact surface of the hollow refractory is suppressed.

In the induction heating tundish according to the first aspect of the present invention, it is preferable that the refractory material is provided on at least the steel receiving part side and the molten steel discharge part side of the molten steel contact surface of the hollow refractory.

In the induction heating tundish according to the first invention, the refractory material is preferably provided in a range satisfying the following relational expression.
L1 / L ≧ 0.1
L2 / L ≧ 0.1
(L1 + L2) /L≧0.4
Here, L is the total length of the hollow refractory, L1 is the length of the refractory material provided on the steel receiving part side of the hollow refractory, and L2 is the length of the refractory material provided on the molten steel discharge part side of the hollow refractory. It is.

In the induction heating tundish according to the first invention, the amount of the CaO component in the refractory material is preferably 10% by mass or more.

The induction heating tundish repairing method according to the second aspect of the present invention has a weir having a hollow refractory forming a molten steel flow path provided at the bottom and provided with induction heating means. An induction heating type tank having a steel receiving portion for receiving molten steel poured from the molten steel, and a molten steel discharge portion for flowing molten steel that flows while being induction heated from the steel receiving portion through the molten steel flow path to a mold In the dish repair method,
A refractory material containing a CaO component is provided on the molten steel contact surface side of the hollow refractory, and the molten steel is caused to flow from the receiving steel portion to the molten steel discharge portion via the molten steel flow path, and the CaO component and molten steel in the refractory material After forming a low melting point compound with the Al ₂ O ₃ component in the casting and suppressing adhesion of deposits to the molten steel contact surface of the hollow refractory, water is applied to the refractory and the hollow The refractory material is removed from the refractory, and the deposits adhered to the molten steel contact surface of the hollow refractory are removed.

In the repair method of the induction heating type tundish according to the second invention, it is preferable that the refractory material is preliminarily covered with a flame before water is applied to the refractory material.

In the repair method of the induction heating type tundish according to the second invention, after the refractory material is removed from the hollow refractory, the molten refractory is made of the same component as the refractory on the molten steel contact surface side. It is preferable to provide the refractory material used.

The induction heating tundish according to claims 1 to 4 and the induction heating tundish repair method according to claims 5 to 7 are provided with a refractory material containing a CaO component on the molten steel contact surface side of the hollow refractory, Since a low melting point compound of CaO-Al ₂ O ₃ system is formed on the molten steel contact surface, a liquid phase with a low melting point is formed on the molten steel contact surface side of the hollow refractory, which is similar to Al ₂ O ₃ inclusions or metal. Adhering or depositing of extraneous matter can be reduced as compared with the prior art. As a result, blockage of the molten steel flow path can be suppressed and further prevented, so that the molten steel flow path can be prevented from becoming thin and the molten steel cannot be heated by the pinch force, enabling casting for a longer time than before, and more stably. The molten steel is heated to ensure the molten steel temperature necessary for casting, and the effect of cleaning the molten steel is also obtained, so that a product of good quality can be manufactured.

In particular, the induction heating tundish according to claims 2 and 3 contains a CaO component on at least the receiving steel portion side and the molten steel discharge portion side of the molten steel contact surface of the hollow refractory that is liable to deposit or deposit. Since the refractory material is provided, the blockage of the molten steel channel can be further suppressed.
Since the induction heating type tundish according to claim 4 regulates the amount of CaO component in the refractory material, a refractory material suitable for suppressing adhesion or accumulation of deposits is disposed on the molten steel contact surface side of the hollow refractory material. it can.

The repair method of the induction heating type tundish according to claims 5 to 7 is such that water is applied to the refractory material during repair of the induction heating type tundish so that the CaO component of the refractory material is digested and the refractory material is easily collapsed. It is possible to easily remove inclusions or bullion that are adhering, and for example, it is possible to reduce the load of repair work or reduce repair costs. For this reason, the load of the cutting by the high temperature combustion flame | frame which has been conventionally used can be reduced, damage of a hollow refractory can be reduced, for example, the lifetime of a hollow refractory can be improved, or trouble due to damage can be prevented.
In particular, the method for repairing an induction heating tundish according to claim 6, even if deposits such as inclusions or metal are deposited on the molten steel contact surface of the hollow refractory, A CaO—FeO-based low-melting-point compound can be generated, and deposits can be easily removed.
In the repair method of the induction heating type tundish according to claim 7, by replacing only the refractory material, the hollow refractory is partially repaired, and the tundish can be reused without replacing the entire hollow refractory.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is a partial side sectional view of an induction heating tundish according to an embodiment of the present invention, FIG. 2 is a side sectional view of a hollow refractory of the induction heating tundish, and FIG. 3 is a hollow refractory. It is explanatory drawing which shows the relationship between the arrangement | positioning area | region of the CaO component containing refractory material and the adhesion amount of a deposit.

As shown in FIGS. 1 and 2, an induction heating tundish (hereinafter also simply referred to as a tundish) 10 according to an embodiment of the present invention is a cylindrical hollow refractory that forms a molten steel channel 11 inside. An object 12 is provided on the bottom 13 and has a weir 14 provided with an induction heating means (not shown). By this weir 14, a steel receiving part 16 for receiving molten steel 15 poured from a ladle (not shown), A molten steel discharge portion 19 is formed for flowing the molten steel 17 flowing from the steel portion 16 through the molten steel flow path 11 while being induction heated to the mold 18. In addition, the discharge amount of the molten steel 17 to the mold 18 is adjusted by a stopper 20 provided in the molten steel discharge portion 19, and the cast steel 21 can be manufactured by cooling the discharged molten steel 17 with the mold 18. This will be described in detail below.

In the present embodiment, the hollow refractory 12 is provided at two locations on the bottom 13 of the weir 14. In addition, the number of the hollow refractories 12 is not limited to this, For example, one place may be sufficient and more than three places may be provided.
The hollow refractory 12 is made of, for example, conventionally used alumina. For example, the hollow refractory 12 is made of alumina graphite refractory (AG), magnesia, or magnesia graphite refractory (MG). You can also The hollow refractory 12 has, for example, a length L of about 0.5 m to 1.5 m (here 1 m), an inner diameter D of about 50 mm to 200 mm (here 180 mm), and a maximum thickness T1 of 20 mm to 50 mm. It is about the following (here 40 mm).
On the inner peripheral surface side that becomes the molten steel contact surface 22 of the hollow refractory 12, for example, dolomite (CaO—MgO system: for example, CaO is 50 mass%) or ZCG (ZrO ₂ —CaO—Graphite: for example, CaO is 22 mass). %)), Refractory materials 23 and 24 containing a CaO component are provided. In addition, thickness T2 of the refractory materials 23 and 24 is smaller than the maximum thickness T1 of the hollow refractory 12, and is about 10 mm or more and 25 mm or less, for example.

The amount of CaO component in the refractory materials 23 and 24 is 10% by mass or more.
If CaO ingredient amounts in the refractory material is less than 10 wt%, CaO-Al ₂ O ₃ system CaO supply amount for forming a low-melting compound is insufficient, Al ₂ O ₃ based on the molten steel contacting surface of the hollow refractory Inclusions or bullion are likely to adhere. Further, at the time of repair, even if the refractory material is heated with a frame (flame), it becomes difficult to generate a CaO—FeO-based low melting point compound, and further, even if water is applied, the refractory material is difficult to collapse.
On the other hand, the above-mentioned effect becomes remarkable as the amount of CaO component increases, so the upper limit is not specified, but when it exceeds 55% by mass, it is caused by the difference in thermal expansion coefficient between the refractory material and other parts. Cracks occur and the lifetime of the hollow refractory is reduced. This is because the coefficient of expansion increases as the CaO content increases, and the refractory material containing CaO generally tends to have a higher coefficient of thermal expansion than refractory materials composed of other components. It is.
From the above, the lower limit of the amount of CaO component in the refractory material is 10% by mass, preferably 15% by mass, more preferably 20% by mass, while the upper limit is 55% by mass, preferably 50% by mass. %.

As shown in FIG. 2, the refractory materials 23 and 24 are provided on at least the steel receiving portion side 25 and the molten steel discharge portion side 26 of the molten steel contact surface 22 to which deposits easily adhere. It may be provided over the entire inner peripheral surface.
Here, the range in which the refractory materials 23 and 24 are provided will be described with reference to FIG. FIG. 3 shows the relationship between the region where the refractory material containing the CaO component is provided on the molten steel contact surface of the hollow refractory and the amount of deposits that could not be removed at that time. L is the total length of the hollow refractory, L1 is the length of the refractory material provided on the steel receiving side of the hollow refractory from the end surface of the steel receiving part, and L2 is the refractory provided on the molten steel discharge side of the hollow refractory. It is the length from the molten steel discharge part side end surface of a material (refer FIG. 2). Moreover, the deposits were removed by spraying the deposits on the molten steel contact surface with a flame using a burner and then applying water. At this time, the amount of the remaining deposits is obtained by cutting the hollow refractory into a plurality of rings in the longitudinal direction and calculating the sum of the remaining deposits. Based on this, the amount of deposits remaining on the molten steel contact surface of the hollow refractory without the refractory material was set to “1”, and the amount of deposits remaining on the hollow refractory with the refractory material was determined as the amount of deposit index. .

As is clear from FIG. 3, the adhesion amount index decreases with an increase in the arrangement region of the refractory material containing the CaO component, and in particular, the adhesion amount index sharply decreases at (L1 + L2) /L=0.4. It can be seen that a significant decrease has occurred. Here, L1 and L2 are substantially the same value.
When (L1 + L2) / L is 0.4 or more, the same results as in FIG. 3 are obtained if both L1 / L and L2 / L are 0.1 or more.
From the above, the refractory materials 23 and 24 are provided in a range satisfying the following relational expression.
L1 / L ≧ 0.1, L2 / L ≧ 0.1, and (L1 + L2) /L≧0.4

In addition, when providing the refractory material in the hollow refractory, the position where the refractory material of the hollow refractory is provided is machined in advance, and, for example, a method of fitting a refractory material previously formed into a ring shape into this part, or A method of providing a refractory material using an irregular refractory material can be used.
Here, when the refractory material is preliminarily molded, the powder material is heated and cured by an electric heater using electric resistance and molded into a ring shape, and then mounted on a machined portion.
In addition, when using an irregular refractory material, a formwork composed of an electric heater is placed in the machined part of the hollow refractory material via a gap, and the refractory material is placed in the formed gap. It is provided by filling and filling, and the worker applies an irregular refractory material using a trowel.

As the refractory material, for example, a material containing a non-aqueous low-temperature thermosetting resin and a high-temperature thermosetting binder can be used. The non-aqueous low-temperature thermosetting resin is, for example, phenol resin powder or acrylic powder, and the high-temperature thermosetting binder is, for example, glass scrap or sodium silicate (SiO ₂ · nNa ₂ O). .
In order to suppress and further prevent reactions of the refractory materials constituting the hollow refractory and the refractory material, zirconia-based mortar is previously applied to the contact surface of the hollow refractory, that is, the machined surface of the hollow refractory. After placement, it is preferred to place a refractory material.

Next, an induction heating tundish repair method according to an embodiment of the present invention will be described with reference to the induction heating tundish 10 described above.
As shown in FIG. 1, when manufacturing the slab 21, molten steel is poured from a ladle (not shown) to the steel receiving part 16, and the molten steel 15 in the steel receiving part 16 is passed through the molten steel flow path 11. Then, the molten steel is supplied to the molten steel discharge portion 19 while being induction-heated, and the molten steel 17 in the molten steel discharge portion 19 is supplied to the mold 18.
In this casting, a CaO-Al ₂ O ₃ low melting point is formed on the molten steel contact surface 22 of the refractory materials 23, 24, that is, the working surface by the CaO component in the refractory materials 23, 24 and the Al ₂ O ₃ component in the molten steel. A compound can be formed, a liquid phase having a low melting point can be formed on the surface, and casting can be performed while suppressing adhesion or deposition of Al ₂ O ₃ inclusions or metal.

In addition, after manufacture of the slab 21 is complete | finished, the hollow refractory 12 of the induction heating type tundish 10 is repaired as needed. The repair work for the hollow refractory 12 is performed with the hollow refractory 12 attached to the weir 14.
In this repair, after the casting of the molten steel is finished, first, the refractory materials 23 and 24 are covered with a flame using a burner. As a result, even if deposits accumulate on the molten steel contact surface 22 of the hollow refractory 12, the refractory materials 23, 24 generate CaO-FeO-based low melting point compounds by cutting the deposits and remove the deposits. Easy to do.

As described above, after the refractory materials 23 and 24 are blown with a flame, water is further applied.
By applying water to the refractory materials 23, 24, the CaO component that is the internal material of the refractory materials 23, 24 is digested (absorbs) and collapses, and the refractory materials 23, 24 are easily removed from the hollow refractory 12, It is possible to remove deposits, and for example, it is possible to reduce the load of repair work or reduce repair costs.
In addition, as described above, after performing a treatment with a flame on a hollow refractory, it is possible to carry out the removal work of the adhering matter with good workability by performing a process of applying water. For example, the adhering amount of the adhering matter is small. As in the case, depending on the state of attachment, only the process of applying water to the refractory material may be performed.
Thus, after removing the refractory materials 23 and 24 from the hollow refractory 12, the refractory material is formed on the molten steel contact surface 22 side of the hollow refractory 12 using a ring-shaped or amorphous refractory material containing a CaO component. An unused refractory material composed of the same components as 23 and 24 is provided. Thereby, it can be reused by exchanging only the refractory material, without exchanging the whole hollow refractory.

After the repair of the hollow refractory 12 is completed, for example, the preheating of the hollow refractory 12 is performed in the range of 800 ° C. to 1200 ° C., and the adsorbed moisture is removed and the hydrate is decomposed by digestion reaction. At the same time, the thermal shock caused by the molten steel pouring is suppressed, peeling is eliminated, the formation of irregularities on the molten steel contact surface 22 is minimized, and the occurrence of cracks is also prevented.
And as shown in FIG. 1, molten steel is poured into the steel receiving part 16 from a ladle (not shown), and the slab 21 is manufactured.
As a result, the amount of deposits adhered to the molten steel contact surface 22 of the hollow refractory 12 during casting can be reduced and further prevented, for example, removal of inclusions by casting for a longer period of time, stable heating, or convection. Is possible. For this reason, the cleaning effect is also obtained and the product results are improved.

Next, examples carried out for confirming the effects of the present invention will be described.
Here, we cast aluminum killed steel using an induction heating tundish with a hollow refractory, repair the hollow refractory after casting, and investigate the amount of deposits remaining and the life of the hollow refractory The results are shown in Table 1. In Table 1, the case where the hollow refractory made of alumina is not repaired is set as a standard (attachment amount index: 1.0, life: 1.0), and the hollow refractory containing the refractory material containing the CaO component is not provided. Conventional example in which deposits were melted using a burner, Example 1 in which a hollow refractory provided with a refractory material was not repaired, Example 2 in which only repair by water cooling was performed, and repair by both burner and water cooling was performed About each of Example 3, the adhesion amount index | exponent which is an operation parameter | index and the lifetime were compared. Here, the adhesion amount index is obtained by cutting the used hollow refractory into a plurality of rings and calculating the total amount of the remaining attachment, as in the above-described method, and the lifetime is the hollow refractory. It means the period until the whole cannot be used repeatedly. Moreover, the refractory material containing the CaO component used in Examples 1 to 3 was ZCG (C: 17.6% by mass, CaO: 22.0% by mass, ZrO ₂ : 59.0% by mass, SiO ₂ : 1. 4 mass%), and the arrangement region of the refractory material is (L1 + L2) /L=0.4.

As is clear from Table 1, by providing a refractory material composed of ZCG to a hollow refractory, even in Example 1 in which repair work is not performed, the degree of improvement in the adhesion amount index and the life is compared with the standard. It was confirmed that it could be improved.
In addition, as in Example 2, the refractory material is only repaired by water cooling, so that the adhesion amount index can be further reduced and the life can be further extended as compared with the conventional example in which frame flame cutting is performed. It was. In addition, by performing repair by water cooling after performing the cutting as in Example 3, the adhesion amount index can be significantly reduced, and the lifetime of the hollow refractory is up to 1.6 times that of the standard. I was able to extend it.
From the above, by using the hollow refractory of the induction heating type tundish of the present invention, the amount of deposits adhering to the molten steel contact surface of the hollow refractory is reduced as compared with the conventional, and the adhered deposits can be removed. It is easy and enables stable casting over a long period of time.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included. For example, the case where the induction heating tundish and the repairing method thereof according to the present invention are configured by combining some or all of the above-described embodiments and modifications are also included in the scope of the present invention.

It is a partial sectional side view of the induction heating type tundish which concerns on one embodiment of this invention. It is a sectional side view of the hollow refractory of the induction heating type tundish. It is explanatory drawing which shows the relationship between the arrangement | positioning area | region of the CaO component containing refractory material to a hollow refractory, and the adhesion amount of a deposit. It is explanatory drawing of the induction heating type tundish which concerns on a prior art example.

Explanation of symbols

10: induction heating type tundish, 11: molten steel flow path, 12: hollow refractory, 13: bottom, 14: weir, 15: molten steel, 16: received steel part, 17: molten steel, 18: mold, 19: molten steel discharge Part, 20: stopper, 21: slab, 22: molten steel contact surface, 23, 24: refractory material, 25: receiving steel part side, 26: molten steel discharging part side

Claims (7)

A hollow refractory forming a molten steel flow path has a weir provided at the bottom and provided with induction heating means. By the weir, a steel receiving part for receiving molten steel poured from a ladle, and from the steel receiving part In the induction heating type tundish in which a molten steel discharge part for flowing molten steel flowing into the mold while being induction heated through the molten steel flow path is formed,
The molten refractory has a refractory material containing a CaO component in part or all of the molten steel contact surface side of the hollow refractory, and in use, in the molten steel flowing through the molten steel flow path with the CaO component in the refractory material. An induction heating tundish characterized in that a low melting point compound is formed with the Al ₂ O ₃ component to suppress adhesion of deposits to the molten steel contact surface of the hollow refractory. 2. The induction heating tundish according to claim 1, wherein the refractory material is provided on at least the receiving steel portion side and the molten steel discharge portion side of the molten steel contact surface of the hollow refractory. Formula tundish. The induction heating type tundish according to claim 2, wherein the refractory material is provided in a range satisfying a relational expression shown below.
L1 / L ≧ 0.1
L2 / L ≧ 0.1
(L1 + L2) /L≧0.4
Here, L is the total length of the hollow refractory, L1 is the length of the refractory material provided on the steel receiving part side of the hollow refractory, and L2 is the length of the refractory material provided on the molten steel discharge part side of the hollow refractory. It is. The induction heating type tundish according to any one of claims 1 to 3, wherein the amount of the CaO component in the refractory material is 10% by mass or more. A hollow refractory forming a molten steel flow path has a weir provided at the bottom and provided with induction heating means. By the weir, a steel receiving part for receiving molten steel poured from a ladle, and from the steel receiving part In the repair method of the induction heating type tundish in which the molten steel discharge part for flowing the molten steel flowing in while being induction heated through the molten steel flow path to the mold is formed,
A refractory material containing a CaO component is provided on the molten steel contact surface side of the hollow refractory, and the molten steel is caused to flow from the receiving steel portion to the molten steel discharge portion via the molten steel flow path, and the CaO component and molten steel in the refractory material to form a low melting point compound and Al ₂ O ₃ component in, after the casting while suppressing the adhesion of deposits to the molten steel contact surface of the hollow refractory, spray water over the refractory material, said hollow A method for repairing an induction heating tundish, characterized in that the refractory material is removed from the refractory to remove deposits adhering to the molten steel contact surface of the hollow refractory. 6. The induction heating type tundish repair method according to claim 5, wherein the refractory material is preliminarily covered with a flame before water is applied to the refractory material. In the repair method of the induction heating type tundish according to any one of claims 5 and 6, after removing the refractory material from the hollow refractory, the refractory material and the molten steel contact surface side of the hollow refractory A repair method for induction heating tundish, characterized by providing unused refractory materials composed of the same components.

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