JP2011104622A - Continuous casting method and ladle for continuous casting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress outflow of inclusions in a molten steel from a ladle when supplying the molten steel from the ladle to a tundish. <P>SOLUTION: A carbon heater 35 is arranged in a lid 31 installed on the ladle 1 when charging the molten steel in the ladle into the tundish 22 of continuous casting equipment from the ladle 1 where the molten steel after secondary refining is stored. The lid 31 is heated by the carbon heater 35 till the charging of the molten steel in the ladle to the tundish 22 is completed after the lid 31 is installed on the ladle 1 set on a turning table 42 of a turret 41. Power is supplied to the carbon heater 35 from a power supply unit 43. Heat released from the lid 31 is reduced, descending flow in the molten steel in the ladle 1 is suppressed, and the floating-up of the inclusions is promoted. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a continuous casting method in which molten steel in a ladle is poured into a tundish of a continuous casting facility from a ladle in which molten steel after secondary refining is stored, and a ladle for continuous casting used in the method. is there.

In continuous casting of steel, molten steel whose components and temperature have been adjusted in the refining process is placed in a refractory container called a ladle and transferred to a continuous casting machine that performs the continuous casting process. More specifically, in a general continuous casting method, the molten steel after secondary refining is transported to the vicinity of a ladle support turning device called a turret by a moving carriage while being stored in the ladle and suspended by a crane. And is set at a predetermined position on the turning table of the ladle support turning device. The ladle support swivel device can turn while supporting two or more ladles on the swivel table. While the molten steel is being poured into the tundish from one ladle, the ladle support swirl device is vacant. Set another ladle with molten steel in the position, and when one ladle is empty, turn the swivel table and move the other ladle to the pouring position. Molten steel is injected into the tank. The ladle support turning device is installed in the vicinity of the upper part of the tundish in the continuous casting facility.
In addition to the turning turret method, there are other methods such as using a cart or exchanging the ladle directly with a crane. The method described below can be applied to any pan changing method.

  And, conventionally, in order to increase the heat retaining property of the molten steel in the ladle, only a lid made of a refractory material is installed on the upper surface opening of the ladle as necessary, and the ladle after secondary refining. For the molten steel at the stage, after being set on the swivel table, no special heating is performed even when pouring into the tundish.

  In addition, as what heats the molten steel in the ladle in the ladle stage, there is a thing which provides a plasma torch on the lid of the ladle and heats and refines the molten steel in the ladle (Patent Document 1). There is no mention of.

  As described above, in the continuous casting method in which the molten steel in the ladle is poured into the tundish of the continuous casting equipment from the conventional ladle in which the molten steel after secondary refining is stored, the molten steel in the ladle to the tundish The ladle itself and the molten steel in the ladle are not heated at the ladle stage after the secondary refining, including during pouring.

JP 58-22212 A

By the way, the molten steel in the ladle has an environment in which the inner wall of the container is made of a refractory, so that the heat release to some extent is suppressed. However, even a 300 t scale ladle is generally about 0.3 ° C. per minute. There is a temperature drop.
That is, the upper part of the molten steel is covered with a molten oxide that is a mixture of CaO, SiO ₂ , Al ₂ O ₃ , MgO and the like that is generally generated by refining called slag, and further, a heat insulating material such as grilled rice or a pan lid is used. In general, the side wall is subjected to heat removal limited by the thermal conductivity of the refractory. Therefore, the temperature of the molten steel becomes lower as the temperature near the refractory wall.

  Since the specific gravity of steel is higher when the temperature is lower in the molten state, when the temperature of the molten steel near the refractory wall decreases, the temperature of the molten steel near the ladle center is low, causing a flow that sinks downward. Thermal convection is formed in the ladle. According to the inventor's thermofluid analysis, the velocity of the downflow near the wall is estimated to be several cm / s to several tens cm / s.

On the other hand, the rising speed of the nonmetallic inclusions in the molten steel basically rises according to Stokes's rising law. That is, if the ascent rate is Vf,
Vf = g (ρ _L −ρ _P ) d _P ² / (18 μ).
Here, g is the gravitational acceleration, ρ _L is the specific gravity of the molten steel, ρ _P is the specific gravity of the inclusion, dp is the diameter of the inclusion, and μ is the viscosity coefficient of the molten steel. Accordingly, for example, when the specific gravity of 3000 (kg / m ³ ), which is a typical example of non-metallic inclusions in defects, is determined, and the flying speed Vf of inclusions having a diameter of 100 μm is obtained, the specific gravity of molten steel is 7200 (kg / m). If m ³ ), the gravitational acceleration is 9.8 (m / s ² ), and the viscosity coefficient of the molten steel is 0.006 (Pa · s), the floating speed of inclusions is about 2.3 mm / s.

  In the ladle, inclusions in the molten steel float up due to the difference in specific gravity with the molten steel, and the floating inclusions are removed, but as described above, the speed of the downward flow at the wall is several cm / s to several tens of cm. In the case of / s, these inclusions do not float but float on the wall in the ladle.

  Molten steel in the ladle is poured into the tundish during continuous casting through a hole formed in the bottom of the ladle and an injection nozzle, etc., but as described above, inclusions do not float but float in the ladle. If so, the inclusions flow into the tundish together with the molten steel. When inclusions flow out of the ladle into the tundish, the inclusions can be lifted and removed to some extent in the tundish, but there are limits to the removal of the inclusions in the tundish, and the continuous casting machine is connected via the tundish. Inclusions flow in the mold of the steel, and the quality of the steel finally produced is lowered.

  As already mentioned, in the process of injecting the molten steel in the ladle after secondary refining into the tundish of the continuous casting equipment, the ladle stage including the time of injecting the molten steel in the ladle into the tundish is included. Then, since the ladle itself and the molten steel in the ladle are not heated, the problem of inclusions in the molten steel due to the downward flow in the ladle caused by heat removal as described above results in The reality is that it is left as it is. For this reason, for example, in steel grades where the upper limit of inclusions is strictly determined, not all of the molten steel in the ladle is allowed to flow out, but an appropriate amount of molten steel is intentionally left in the ladle. Although there are examples in which inclusions are prevented from flowing in, it is clear that this method reduces the production efficiency and cannot be a drastic measure.

  This invention is made | formed in view of this point, and when a molten steel is inject | poured into a tundish from a ladle, it aims at suppressing the inclusion in a molten steel flowing out from a ladle.

As described above, the cause of the downward flow formed in the ladle is the temperature drop of the molten steel. Therefore, the amount of heat removal causing the temperature drop was specifically examined.
As a result, the amount of heat removed from the refractory on the side wall and bottom of the ladle was found to be about 5 kW / m ² when determined from the measured values of the temperature of the refractory in the actual ladle.
On the other hand, the amount of heat removed from the surface of the slag on the molten steel in the ladle is radiated through radiation and convection heat through a space filled with gas, and is removed through a lid covered with a refractory. As a result of heat transfer calculation, it was estimated to be about 10 to ²⁰ kW / m ² .
As described above, it has been found that the heat removal from the lid is much larger than the heat removal from the side wall and the bottom. Accordingly, the present invention has been achieved based on the idea that the downflow velocity can be most effectively reduced by heating the lid itself to suppress heat removal from the lid. That is, in order to achieve the above object, the present invention provides a continuous casting method in which molten steel in a ladle is poured into a tundish of a continuous casting facility from a ladle in which molten steel after secondary refining is stored. A resistance heating body is provided in the lid to be installed, and after the lid is installed on the ladle set on the ladle support stand located above the tundish, the molten steel in the ladle is injected into the tundish Until the process is completed, the lid itself is heated by the resistance heating body.

  Thus, after installing the lid | cover which has a resistance heating body with respect to the said ladle set to the ladle support stand, until the completion of injection | pouring of the molten steel in a ladle to the said tundish, the said resistance heating Heat removal from the lid is suppressed by heating the lid itself with the body. Therefore, heat dissipation from the molten steel surface of the molten steel in the ladle is suppressed, and as a result, the speed of the downward flow at the wall generated by heat removal from the ladle can be reduced, and the floating of inclusions can be promoted. . Therefore, it can suppress that the inclusion in molten steel flows out from a ladle to a tundish. In addition, as described above, the heat removal from the lid is much larger than the heat removal from the side wall and the bottom, so it is most effective by suppressing the heat removal from the lid by heating the lid itself. The flow rate of the downward flow can be reduced.

  In the present invention, after the lid is installed on the ladle, the heating of the resistance heating body is started, and until the injection of the molten steel in the ladle into the tundish is completed, the inner surface of the lid It is preferable to control the temperature to 800 ° C. or higher.

  In the present invention, before the lid is installed on the ladle, the resistance heating body is heated in advance to preheat the inner surface temperature of the lid to 800 ° C. or higher, After installing the preheated lid on the pan, the inner surface temperature of the lid may be maintained at 800 ° C. or higher until the pouring of molten steel in the ladle into the tundish is completed.

  The ladle for continuous casting according to the present invention is a ladle used when the above continuous casting method is carried out, and has a lid that covers the upper surface opening of the ladle, and a resistance heating element is provided inside the lid. It is characterized by being provided.

  ADVANTAGE OF THE INVENTION According to this invention, when supplying molten steel from a ladle to a tundish, it can suppress that the inclusion in molten steel flows out from a ladle.

It is explanatory drawing of the longitudinal cross-section which shows the outline of the structure of the ladle concerning embodiment typically. It is explanatory drawing which shows a mode that the ladle was set to the turret. When a lid heated to a certain temperature is installed in a ladle containing molten steel, and the molten steel is poured into the tundish from the ladle, the temperature inside the lid and the residual molten steel in the ladle after the completion of the tundish injection It is the graph which showed the relationship with the number of inclusions.

Embodiments of the present invention will be described below. FIG. 1 is an explanatory view of a longitudinal section showing an outline of the configuration of a ladle 1 according to the present embodiment, and the ladle 1 has a hollow substantially cylindrical shape with a side wall 10 and a bottom portion 11. Molten steel M can be stored inside.
Both the side wall 10 and the bottom 11 are composed of a wear brick 12, a permanent brick 13, and an iron skin 14 in that order from the inside. An outlet 20 is formed in the bottom 11. An injection nozzle 21 that extends downward is connected to the outlet 20. By this outflow port 20 and the injection nozzle 21, the molten steel M in the ladle 1 can be supplied to the tundish 22 provided below the ladle 1 as shown in FIG.

  The upper surface of the ladle 1 is opened, and a detachable lid 31 that covers the opening surface is provided on the upper surface. The lid 31 is also composed of a wear brick 32, a permanent brick 33, and an iron skin 34 in order from the inside. As a resistance heating body, for example, a carbon heater 35 is provided between the wear brick 32 and the permanent brick 33. This carbon heater 35 generates heat by supplying electric power, and can heat the surface of the lid 31 on the inner side of the wear brick 32 (molten steel M side) to an arbitrary temperature of about 1000 ° C. to 1500 ° C.

  The surface of the molten steel M stored in the ladle 1 is covered with slag S, which is a molten oxide generated in the refining process, and the space between the inner side surface of the lid 31 and the slag S contains air A Is present.

  The ladle 1 according to the embodiment has the above-described configuration. Next, a continuous casting method using the ladle 1 will be described.

  The ladle 1 in which the molten steel after the secondary refining is stored is transported to the vicinity of the turret 41 of the continuous casting facility shown in FIG. 2 by a moving carriage (not shown), and the turret 41 is moved by a crane (not shown). The swivel table 42 is set at a predetermined position. The turning table 42 is turned by a driving mechanism (not shown) such as a motor, and a plurality of ladles can be placed on the turning table 42. The swivel table 42 is usually disposed near the tundish 22 of the continuous casting machine 23.

A lid 31 is installed on the upper surface opening of the ladle 1 set at a predetermined position of the turning table 42 of the turret 41 by a crane (not shown). Then, electric power is supplied to the carbon heater 35 to control the inner surface of the wear brick 32 of the lid 31 to a temperature of 800 ° C. to 1500 ° C. The higher the rate of temperature increase, the better. However, a commercially available heater can usually be increased to a desired temperature within about 5 minutes. After reaching the desired temperature, the heater may be controlled so that it does not fall below the desired temperature.
Moreover, the lid | cover 31 may supply the electric power to the carbon heater 35 beforehand at the time of a standby state, and may heat the inner surface of the wear brick 32 of the lid | cover 31 to the temperature of 800 to 1500 degreeC.
It should be noted that the time from the installation of the lid to the ladle to the completion of the pouring of the molten steel in the ladle into the tundish is about 30 minutes, whereas in the case of a normal heater, the heating time of the heater Since it is within about 5 minutes, even when the lid is not preheated, the effect of reducing the flow rate of the downflow of the molten steel in the ladle can be fully enjoyed as compared with the case where the lid is preheated.
The power supply is performed through a cable 44 from a power supply unit 43 provided on the turntable 42, for example.

  Next, when the other ladle 1 ′ already set on the swivel table 42 and injecting molten steel into the tundish 22 has completed the pouring, the swivel table 42 immediately turns and the ladle 1 moves to the pouring position. Then, pouring of molten steel in the ladle into the tundish 22 is started. And while this ladle 1 is pouring molten steel, other ladle 1 'is collect | recovered from the turning table 42, and the other ladle which stored the molten steel newly is set to the position instead. .

  Electric power is supplied to the carbon heater 35 until the pouring from the ladle 1 into the tundish 22 is completed, while the lid 31 is heated. As a result, heat removal from the lid 31 is suppressed, the speed of the downward flow at the inner wall of the ladle caused by heat removal from the ladle can be reduced, and the floating of inclusions can be promoted. Therefore, it is possible to suppress the inclusions in the molten steel from flowing out from the injection nozzle 21 to the tundish 22.

  Actually, the inventors investigated the change in the speed of the downward flow of the molten steel in the ladle when the temperature of the inner surface of the lid was changed using the general-purpose thermal fluid analysis software FLUENT.

In the analysis, first, the ladle dimension is a cylinder of 4 m in diameter and 3 m in height, and the heat removal from the side wall and the bottom surface is obtained from the measured value of the temperature of the refractory etc. of the actual ladle as described above. / m were fixed with ^2, the inner surface temperature of the lid is analyzed condition 4 is the level change that is controlled to a constant value. The analysis conditions are as follows. First, slag having a thickness of 15 cm exists on the molten steel surface, and air at 27 ° C. is present on the upper surface of the slag, and the convective heat transfer coefficient to the air is 1.5 W / m ² · K. It was. The convective heat transfer coefficient was obtained by conducting a separate experiment. Since the temperature of the air actually rises due to heating from the molten steel, the assumption that it is constant at 27 ° C. is set in a direction in which the amount of heat removal increases, that is, under conditions that are more severe than actual. However, since the heat transfer between the slag and the refractory inside the lid is dominated by radiation and the contribution of the convection heat transfer is very small, even if the air temperature is set under severer conditions than the actual Almost no problem.

The basic idea of the thermo-fluid analysis is that when the temperature of the inner surface of the lid is controlled to a constant value and when a certain amount of heat is removed from the side wall and bottom surface of the ladle. The initial value of the molten steel temperature in the pan was set, the temperature change of the molten steel was calculated by the above heat removal, and the downward flow was calculated corresponding to the temperature decrease. Here, the molten steel was treated as a liquid, but the slag was poor in fluidity, so that the analysis was performed assuming that it was a solid for convenience.
This will be described in detail below.

First, the following equation was used as the boundary condition for the slag upper surface temperature.
_{^{σε (T s 4 -T f 4}} ) + h (T s -T A)
Here, σ is the Stefan-Boltzmann constant, and ε is the emissivity, but the emissivity depends not only on the substance but also on the surface state, etc., and is 0.60 to 0.90 for iron oxide and 0.30 for Al oxide. The numerical range is wide with 0.75 to 0.95 for bricks of ~ 0.76. The molten slag is composed of Ca, Al, Si, Mg oxide, and the like, and the composition changes variously. Here, 0.5 is used as an average value. T _f is the inner surface temperature of the lid, T _s is the slag upper surface temperature, and T _A is the air temperature.

The heat flow in the ladle can be obtained by solving the Naviestokes equation together with the continuous equation and the energy conservation equation. Here, the equations are discretized and solved by a finite volume method using general-purpose thermal fluid analysis software (FLUENT). That is, the thermal fluid analysis was performed, the temperature change of the molten steel in the ladle due to heat radiation was calculated with a fine mesh, and the flow state of the molten steel was calculated over time in consideration of the increase in specific gravity due to the temperature drop.
As for physical properties, the density of steel is 7200 kg / m ^{3 at} 1803K, the thermal expansion coefficient is 1.25 × 10 ⁻⁴ / K, the specific heat is 750 J / kg · K, the thermal conductivity is 45 W / m · K, the viscosity The coefficient was set to 0.006 Pa · s. The density of the slag was set to 3000 kg / m ³ at 1803K, the specific heat was set to 65 J / kg · K, and the thermal conductivity was set to 1.5 W / m · K. The boundary condition of flow was free slip in meniscus, the standard wall function was used for the wall surface, and the heat transfer boundary condition was a heat flux of 5 kW / m ^{2 on the} wall surface and bottom surface.
The initial temperature of the molten steel was 1843K, and the unsteady heat flow analysis was performed. The density change due to thermal expansion was an incompressible flow, and the Businesque approximation was used, taking into account the effect of buoyancy. Moreover, since the turbulent model is a flow including a laminar flow region, the RNGk-ε model was used. (For models such as turbulent model and Bushnesque approximation, see, for example, the Japan Fluid Dynamics Society edition, Fluid Mechanics Handbook, published on July 20, 1987, Maruzen Co., Ltd. Is described on page 178, the RNGk-ε model is V. Yakhot
and SA Orszag. Renormalization Group Analysis of
Turbulence: I, Basic Theory. Journal of
Scientific Computing, 1 (1): 1-51, 1986.12-12).

  Table 1 shows the results obtained by the above analytical calculation.

  According to this result, it was found that the maximum value of the downward flow velocity at the inner wall of the ladle decreases as the inner surface temperature of the lid increases, and the downward flow can be significantly suppressed. Therefore, the floating of inclusions can be promoted. Accordingly, it is possible to suppress inclusions in the molten steel from flowing out from the injection nozzle 21 to the tundish 22.

  As described above, it was found that raising the inner surface temperature of the lid to lower the flow velocity of the downflow of the side wall, the inventors further verified that the purpose is to raise the inclusions of molten steel in the ladle It was newly discovered that a suitable inner surface temperature exists.

FIG. 3 shows a case where the temperature of the inner surface of the lid installed on the ladle storing molten steel is controlled to a constant temperature by using the thermal fluid analysis and the Stokes levitation law. It is the graph which showed the relationship with the number of inclusions in the residual molten steel in a ladle after completion of tundish injection (after 30 minutes from the time of installing a lid on the ladle) when molten steel was poured into the tundish from . In addition, the inner surface setting temperature of the lid was set to 27 ° C to 1570 ° C in increments of 250 ° C.
Incidentally, when controlling to a constant temperature of 27 ° C., the temperature of the inner surface of the lid actually increases due to the heat received from the molten steel, so it is necessary to cool the lid. In order to analyze the influence of side temperature, such a calculation was performed.
As a result, the residual concentration in the ladle of each inclusion of 50 μm diameter, 100 μm diameter, and 150 μm diameter after 30 minutes of calming was set to 1 when the inner surface temperature of the lid was set to 27 ° C. The graph shown in FIG. 3 shows values.

According to this, it can be seen that the inclusion index is significantly reduced (halved) for inclusions with a diameter of 150 μm from the temperature of the inner surface of the lid of about 800 ° C. Therefore, when heating the inner surface temperature of the lid with a resistance heating element, if the temperature of the inner surface of the lid is 800 ° C. or higher, inclusions with a diameter of 150 μm can be appropriately levitated and the inflow into the tundish can be prevented. Can be suppressed.
Moreover, if it is set to 1000 ° C. or higher, inclusions having a diameter of 100 μm can be appropriately levitated, and if it is set to 1200 ° C. or more, inclusions having a diameter of 50 μm can be levitated appropriately. It can be seen that the desired temperature may be set according to the quality.
In addition, since there is no effect for inclusion reduction even if heated above the molten steel temperature, the upper limit temperature for heating is the temperature of the molten steel stored in the ladle, for example, about 1500 ° C. to 1600 ° C. is the practical upper limit. Become.

In addition, as for the supply of electric power to the resistance heating body, it is sufficient that the lid is placed in the ladle and then the injection of the molten steel in the ladle into the tundish is completed, so long as it is controlled to a desired temperature or higher. It is not always necessary to supply power, and the power may be supplied intermittently or may be stopped halfway. For temperature control, a widely known method such as PID control may be employed.
By the way, the temperature of the molten steel after the completion of secondary refining will decrease immediately thereafter. For example, when it is set on the ladle support stand (after 30 minutes have passed since the second refining), it usually reaches about 700 ° C. If the temperature is lower than normal, it is preferable to preheat the lid before the lid is placed on the ladle set on the ladle support.

  Hereinafter, the inclusion outflow suppression effect of the molten steel in the actual machine when the ladle, molten steel, and refractory according to the above-described embodiment are used will be described. First, the target ladle used a cylindrical 300t molten steel ladle, secondarily refined on a carriage, transported to a separate building without a lid, and set on a turret using a crane. Then, 30 minutes after the completion of the secondary refining, the ladle was covered, and then the injection was started at 10 t / min into the 2-strand tundish, which was then injected for about 30 minutes.

During the injection, the diameter of the molten steel sample in the tundish taken from the injection nozzle to the tundish for 30 minutes every 30 minutes (typical name of 25-75 μm), 100 μm (typical name of 75-125 μm), 150 μm (125-125) 175 μm (typical name) was taken out by electrolytic extraction, and the number was counted and averaged, and the relative number was arranged based on the number when there was no preheating / heating described later. As a condition, the ladle used as a standard was a steel outer wall of 30 mm, a siliceous permanent brick of 60 mm, an alumina wear brick of 30 mm, and an alumina castable of 180 mm. The average heat removal amount from the side wall and the bottom surface calculated by actually measuring the temperature was 5 kW / m ² . The lid that covers the top of the ladle includes a normal lid (comparative example: ordinary steel outer wall 30 mm, siliceous perma brick 60 mm, alumina board 20 mm), a resistance heater built-in lid (example: ordinary steel outer wall 30 mm, siliceous) Perma brick 60 mm, graphite resistance heating zone 20 mm, silicon carbide refractory 20 mm) were used for comparison.

  A plurality of thermocouples are installed on the inner wall surface of the lid and preheated to about 800 ° C, about 1000 ° C, and about 1500 ° C while measuring the temperature. After the lid is installed, the resistance heating element is kept at about 800 ° C. (Example 1), about 1000 ° C. (Example 2), and about 1500 ° C. (Example 3) until the injection is completed after the lid is installed. The power supply was controlled. The heating conditions were as shown in Table 2, and after the ladle was moved to the turret, a preheated lid was placed on the ladle and connected to the power source via the turret and heated. As can be seen from the results shown in Table 2, significant inclusion reduction effect was obtained by heating the lid. Incidentally, the inner temperature of the lid under the preheating / no heating condition (comparative example) was about 750 ° C. when the molten steel injection was completed due to the radiant heat from the molten steel.

  In addition, without preheating the lid, after installing the lid on the ladle, heat immediately, and within 5 minutes, raise the temperature to about 800 ° C, about 1000 ° C, and about 1500 ° C, and then maintain each temperature. Thus, substantially the same result was obtained when the power supplied to the resistance heating element was controlled.

  INDUSTRIAL APPLICATION This invention is useful for the continuous casting method which inject | pours the molten steel in a ladle into the tundish of a continuous casting installation from the ladle which stored the molten steel after secondary refining.

DESCRIPTION OF SYMBOLS 1, 1 'Ladle 10 Side wall 11 Bottom part 12, 32 Wear brick 13, 33 Permanent brick 14, 34 Iron skin 20 Outlet 21 Injection nozzle 22 Tundish 23 Continuous casting machine 31 Lid 35 Carbon heater 41 Turret 42 Turning table 43 Power supply Supply section 44 Cable A Air M Molten steel S Slag

Claims (4)

In a continuous casting method in which molten steel in a ladle is poured into a tundish of a continuous casting facility from a ladle in which molten steel after secondary refining is stored,
Provide a resistance heating element in the lid installed in the ladle,
After the lid is installed on the ladle set on the ladle support stand located above the tundish, the lid itself is between the completion of the pouring of molten steel in the ladle into the tundish. Is heated with the resistance heating element. After the lid is installed on the ladle, the heating of the resistance heating body is started and the inner surface temperature of the lid is set to 800 until the injection of molten steel in the ladle into the tundish is completed. 2. The continuous casting method according to claim 1, wherein the continuous casting method is controlled to be equal to or higher than ° C. Before the lid is installed on the ladle, the resistance heating body is heated in advance, and the inner surface temperature of the lid is preheated to 800 ° C. or higher, and the preheating is performed on the ladle. 2. The inner surface temperature of the lid is maintained at 800 ° C. or higher until the molten steel in the ladle is completely poured into the tundish after the lid is installed. Continuous casting method. A ladle used for carrying out the continuous casting method according to any one of claims 1 to 3,
It has a lid that covers the top opening of the ladle,
A continuous casting ladle, wherein a resistance heating body is provided inside the lid.

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