JP2000202586A - Cooling drum for twin drum type strip continuos casting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To profitably dissolve the wearing problem of the end surface part of drum, to restrain the abnormal growth of the stuck metal and to realize the stable continuous casting for a long term by forming a heat-insulating layer having a specified value or lower of the thermal conductivity on the end surface of the drum. SOLUTION: On the end surface 18 of the cooling drum 1b in a twin drum type strip continuos casting apparatus provided with one pair of cooling drums 1 mutually rotated in the reverse direction and one pair of side weirs 2 press-fixed to both end surfaces thereof, the heat insulating layer 9 having <=10 W/m.K thermal conductivity, is formed. In this way, the wear of the cooling drum 1 slidingly moved with the side weir 2 is restrained and the shape is stably secured for long time and the heat- transferring from the end surface 1p of the drum is suitably restrained and the stable continuous casting can be realized for the long term by restraining the growth of the stuck metal at the side weir 2 and the end surface 1p of the drum. Then, it is desirable to set the heat-insulating layer 9 under consideration of the relation between the thickness and the thermal conductivity for stably securing the balance of the restraint to the heat transferring and deterioration caused by heat-up itself.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling drum used in a twin-drum continuous thin-plate casting apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 3, a twin-drum continuous thin-plate continuous casting apparatus generally known from the prior art has a pair of rotating cooling drums 1a and 1b and a pair of rotating cooling drums 1a and 1b abutting both end surfaces of the drum. The molten metal 6 is supplied from the inside of the tundish 4 through the nozzle 5 into the moving mold 3 formed by the side weirs 2 of the type, and the pool 3p of a predetermined level is formed in the moving mold 3.
The solidified shell 6s is formed by cooling with the pair of cooling drums 1a and 1b while the solidified shell 6s is formed, and the solidified shell 6s is pressed and integrated at the gap formed at the closest part of the pair of cooling drums 1a and 1b. The thin plate 6c is configured to be continuously cast.

[0003] A pair of cooling drums 1a and 1b used in this twin-drum thin sheet continuous casting apparatus are generally formed of Cu or Cu alloy having good thermal conductivity. As shown in FIG. In order to form a solidified shell 6s by cooling on the outer peripheral surface and to ensure durability against a thermal load, a cooling structure 7 is provided inside as shown in FIG. A protruding end 1t is formed at an end of the cooling drum 1, and a side weir 2 is pressed against the end surface 1p, and the end surface 1p is worn by sliding with the side weir.

[0004] In particular, an uneven gap is easily formed between the side weir 2 due to vibration and thermal deformation of the side weir 2, and molten steel enters and solidifies in this gap, and irregularities are generated on the sliding surface. As a result, the molten steel sealing function on this sliding surface is sharply reduced and the side end shape of the thin cast piece is impaired, and the wear of the cooling drum end surface and the side dam is promoted, and the life is shortened and the life is shortened. A stable continuous casting operation cannot be realized.

In order to solve such a problem, for example, in Japanese Patent Application Laid-Open No. Hei 6-336755, as shown in FIG. 1A, an end face 1p of a cooling drum 1 is provided with high strength, wear resistance and lubricity. It has been proposed to form a coating layer 8 made of, for example, a Co—Cr—Al—Y-based alloy having the above-mentioned or ceramics such as WC.

The cooling drum 1 is, as described above,
A cooling structure 7 is provided in the inside, and a device has been devised to enhance the cooling of the protruding end of the drum in order to equalize the surface temperature in the width direction and reduce the thermal load on the protruding end 1t. However, in particular, the end face 1p of the protruding end 1t of the drum that slides with the side weir 2
As a result, the side weir 2 becomes excessively heat-dissipated, causing abnormal growth of the metal in the side weir 2, making it difficult to continue the continuous casting operation early.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a twin-drum type thin plate capable of realizing stable continuous casting over a long period of time by effectively solving the problem of abrasion and suppressing abnormal growth of a metal at the end face of a cooling drum. A cooling drum for a continuous casting apparatus is provided.

[0008]

The present invention provides the following (1).
To (7). (1) In a cooling drum used in a twin-drum continuous casting apparatus having a pair of cooling drums rotating in opposite directions and a pair of side dams pressed on both end surfaces of the cooling drum, heat is applied to the drum end surface. Conductivity 10 W / m
A cooling drum for a twin-drum thin sheet continuous casting apparatus, wherein a heat insulating layer of K or less is formed. (2) A cooling drum used in a twin-drum continuous sheet casting apparatus having a pair of cooling drums rotating in opposite directions and a pair of side dams crimped on both end surfaces of the cooling drum. When the thickness of the heat insulating layer obtained is t and the thermal conductivity is λ, the following formula (1 / t) × λ = 10 ² W / m ² · K to 10 ⁴ W / m ²
A cooling drum for a twin-drum continuous sheet casting apparatus, wherein the thickness t and the thermal conductivity λ of the heat insulating layer made of the low thermal conductivity material are set so as to satisfy K 1. (3) In a cooling drum used in a twin-drum continuous sheet casting apparatus having a pair of cooling drums rotating in opposite directions and a pair of side dams pressed on both end surfaces of the cooling drum, a drum body is provided. Thermal conductivity is 100W / m
・ Made of a material of K or higher, with a thermal conductivity of 3 W on the drum end surface
A cooling drum for a twin-drum continuous thin-plate casting apparatus, wherein a heat insulating layer is formed by coating a low thermal conductivity material having a thickness of 10 to 10000 [mu] m or less by thermal spraying or overlaying. (4) A cooling drum for a twin-drum continuous sheet casting apparatus according to any one of (1) to (3), wherein the hardness at room temperature (Hv 100 g) of the heat insulating layer formed on the drum end surface is 200 or more. (5) The twin-drum type according to any one of (1) to (4), wherein the ratio of the thermal expansion coefficient of the heat insulating layer formed on the end face of the drum to the thermal expansion coefficient of the drum body member is 50 to 120%. Cooling drum for continuous sheet casting equipment. (6) In any one of the constitutions (1) to (5), the outer peripheral surface of the drum body has a heat conductivity of 30 W / m · K or more and a thickness of 10
A cooling drum for a twin-drum thin-sheet continuous casting apparatus, wherein a heat transfer layer of up to 5000 μm is formed. (7) In any one of (1) to (6), an intermediate layer having a thermal conductivity of 30 W / m · K or more and a thickness of 10 to 5000 μm is interposed between the drum body member and the heat insulating layer. Cooling drum for twin-drum continuous sheet casting equipment.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the abrasion of the end of the cooling drum that slides with the side weir is suppressed to secure the shape over a long period of time, and the heat removal from the drum end is appropriately suppressed. By suppressing the growth of the metal between the side weir and the end face of the drum, stable continuous casting is realized over a long period of time.

Therefore, in the invention (1), it is necessary to form a heat insulating layer having a thermal conductivity of 10 W / m · K or less on the end face of the drum. If the thermal conductivity exceeds 10 W / m · K, the effect of suppressing heat removal is not sufficient, and the growth of the base metal cannot be suppressed. Further, in the invention of the above (2), when a heat insulating layer made of a material having a low thermal conductivity is formed on the end face of the drum, the heat insulating layer is required to stably maintain a balance between the suppression of heat removal and the deterioration due to the temperature rise of the heat insulating layer. It is preferable to set in consideration of the relationship between the thickness t of the layer and the thermal conductivity λ.

The present inventors have conducted experiments and found that when the cooling conditions by the internal cooling structure were kept constant, (1 / t) × λ = 10 ² W / m ² · K to 10 ⁴ W / m ²
It has been confirmed that if the thickness t and the thermal conductivity λ of the low thermal conductivity material are set so as to satisfy K 1, the balance between the suppression of heat removal and the deterioration due to the temperature rise of the material itself can be stably secured.

In the case of (1 / t) × λ <10 ² W / m ² · K, the heat insulating effect is insufficient and the growth of the metal cannot be sufficiently suppressed. (1 / t) × λ> 10 ⁴ W / m ² · K
In the case of (1), the heat insulating effect is too large, the surface temperature of the outer periphery of the drum end increases, and the low heat conductive material is easily oxidized or worn, which is not preferable.

Further, in the invention of (3), the drum body of the cooling drum is formed of a high thermal conductivity material having a thermal conductivity of 100 W / m · K or more, and the cooling effect of the drum body by the internal cooling structure is obtained. In addition to increasing the thickness, the thickness of the drum end face that is likely to deform and
A heat insulating layer is formed by coating a low thermal conductivity material having a thermal conductivity of 3 W / m · K or less at 0 to 10000 μm, thereby suppressing heat removal from the drum end face and suppressing growth of the base metal.

Although the wear of the end of the cooling drum is affected by the material forming the side weir, the present invention assumes that a cooling drum more expensive than the side weir is used for a long period of time. Hardness of sliding surface (Hv 100
g) is based on the premise that the ceramic material is formed of up to about 200 ceramic materials.

Therefore, in addition to the above conditions, the low thermal conductivity material for forming the heat insulating layer on the drum end surface that slides on the side weir has a hardness (Hv 100 g) at room temperature of the sliding surface of the side weir. Hardness (Hv 100 g) or more is preferable, and hardness (Hv 100 g) is 200 or more S
_{iO 2, ZrO 2, ZrO 2} -CoCrAlY, 62A
1-10Cr-10Fe-18Co, Al-Cu-Fe
Using -Cr or the like can also suppress wear at the drum end. If the hardness Hv is less than 200, the effect of suppressing wear cannot be sufficiently ensured.

In the present invention, the high thermal conductivity material used for the drum body is preferably made of Cu, Cu alloy or the like having a thermal conductivity of 100 W / m · K or more in order to improve the transmission of cooling by the internal cooling structure. is there. When the thermal conductivity is less than 100 W / m · K, the transfer of cooling to the drum surface and the drum end surface is not sufficient.

As a means for coating the low thermal conductivity material for forming the heat insulating layer, thermal spraying or overlaying capable of relatively easily and firmly coating between different materials is used, and the thickness of this coating is 10 to 10000 μm. It is preferable to select within a range. A coating with a thickness of less than 10 μm is liable to wear and it is difficult to maintain a long life. On the other hand, a coating of 10,000 μm or more is uneconomical because it results in an excessive coating and an increase in cost.

The coefficient of thermal expansion of the low thermal conductivity material forming the heat insulating layer at the end of the drum is such that the difference in thermal expansion from the drum body member is small in order to ensure sufficient bonding strength with the drum body member. In this sense, it is preferable that the ratio with the coefficient of thermal expansion of the drum body member be 50 to 120%. If it is less than 50% and more than 120%, the heat-insulating layer is peeled off early and the effect of the heat-insulating layer cannot be stably maintained for a long time.

The heat-insulating layer made of a material having a low thermal conductivity may be formed by directly spraying or building up a drum body made of a material having a high thermal conductivity, but the heat-insulating layer may be made of a relatively hard material such as SiO _2. When formed of a small ceramic material, it is effective to interpose an intermediate layer in order to secure the formation strength of the heat insulating layer and to stably secure the strength of the protruding end of the drum.

As a material for forming the intermediate layer, the thermal conductivity is 30 W / m · K or more, the adhesion between the drum body member and the heat insulating layer by thermal spraying or overlaying is good, and the hardness (Hv 100
g) is larger than the hardness of the drum body member and has a reinforcing function, for example, Ni, Cr, Co-based material is suitable.

The intermediate layer in this case also functions as a heat transfer layer, and has a thermal conductivity of 30 W / m · K or more.
It is preferable that the protruding end can be appropriately cooled by an internal cooling structure, and the thickness of the intermediate layer is 10 to 5000 μm.
It is preferable to set the degree. If the thickness is less than 10 μm, sufficient strength cannot be obtained. If the thickness is more than 5000 μm, the formation cost increases and the film tends to peel off due to the difference in thermal expansion coefficient.

The coefficient of thermal expansion of the material forming the intermediate layer is preferably such that the difference in thermal expansion between the drum body member and the heat insulating layer is small in order to ensure sufficient bonding strength between the drum body member and the heat insulating layer. In that sense, it is preferable to set the ratio of the thermal expansion coefficient of the drum body member to 50 to 120%. If it is less than 50% and more than 120%, the intermediate layer is separated from the drum body member and the heat insulating layer at an early stage, and the effect of the heat insulating layer cannot be stably maintained for a long time.

Further, in order to stabilize the cooling heat transfer on the outer peripheral surface of the drum, a heat conductivity of 30 W / m · K
As described above, a material having good adhesion by thermal spraying or overlaying with the drum body member, for example, a Ni, Cr, or Co material is suitable. It is preferable that the thickness of the heat transfer layer be about 10 to 5000 μm. If the thickness is less than 10 μm, sufficient strength cannot be obtained. If the thickness is more than 5000 μm, the formation cost increases and the film tends to peel off due to a difference in thermal expansion coefficient, which is not preferable.

The intermediate layer and the heat transfer layer may be formed independently or may be formed continuously. Since heat transfer is performed between the drum body, the intermediate layer and the heat transfer layer, in order to improve the heat transfer efficiency, thermal spraying, overlaying, plating, and the like that can easily cover a tight junction from the outside are preferable. . In the case where the thermal conductivity of the intermediate layer and the heat transfer layer is less than 30 W / m · K, particularly when the thickness is increased, the drum end cannot be cooled appropriately, and the strength of the drum protruding end is reduced. Not preferred.

[0025]

FIG. 1 is a structural example of a cooling drum according to the present invention.
A description will be given based on the embodiment shown in FIG. In FIG.
1a is a conventional standard cooling drum shown in FIG.
A protruding end 1t having a width of x1 to 10 mm and a height of h1 to 20 mm is formed in a ring shape at an end to which the side weir 2 is abutted.
The end face 1p of the protruding end 1t and the end face 1 of the drum body 1b
An inclined surface 1c having an inclined angle θ of less than 80 degrees is formed between f, and the body 1b is provided with a cooling structure 7.

In the present invention, in the cooling drum 1a having such a structure, the drum body 1b is set at 100 W / m ·
The end face 1 of the protruding end 1t which is formed of a material having a high thermal conductivity of K or more and is likely to be worn by contact with the side weir 2 and the solidified shell.
p has a thickness t of 10 to 10000 μm and a thermal conductivity of 3 W /
The heat insulating layer 9 is formed by coating a low thermal conductivity material of m · K or less to suppress the heat removal from the end face 1p of the protruding end 1t, thereby suppressing the growth of the metal.

In some cases, the heat insulating layer 9 may be formed directly on the material of the drum body 1b. However, when sufficient formation strength cannot be obtained, as shown in FIG. For example, a Ni plating layer having a higher hardness than the drum body 1b is interposed as the intermediate layer 10 between the heat-insulating layer 9 at the protruding end 1t and the heat-insulating layer 9 at the protruding end 1t. It is preferable to secure them. It is more preferable to secure the cooling effect of the internal cooling structure 7 on the protruding end 1t. Further, it is preferable to form, for example, a Ni plating layer having a thickness of 10 to 5000 μm as the heat transfer layer 11 on the outer periphery of the drum body 1b. Here, the intermediate layer 10 and the heat transfer layer 11 are formed continuously.

[0028]

Experimental Example In this experiment, the thermal conductivity of the drum body 1b and the protruding end 1t of the cooling drum as shown in FIG.
m · K, hardness Hv150, coefficient of thermal expansion 18 × 10 ⁻⁶ /
And a heat transfer layer 1 on its outer peripheral surface.
The thermal conductivity is 90 W / m · K and the hardness (Hv 10
0g) 200, Ni plating having a thermal expansion coefficient of 16 × 10 ⁻⁶ / ° C. and a thickness of 1000 μm, and a thermal conductivity of 90 as an intermediate layer 10 on the end face 1p of the drum protruding end 1t.
W / m · K, hardness (Hv 100 g) 200, thermal expansion coefficient 16 × 10 ⁻⁶ / ° C. Ni plating with a thickness of 1000 μm is applied, and the heat insulating layer 9 is formed on the upper surface of the cooling drum. is there.

In this experiment, the casting speed was set to 4 using a material for forming the heat insulating layer 9 and a cooling drum manufactured by changing the forming conditions.
Continuous casting of thin slab 10t with a thickness of 3mm at 0m / min.
Of the sliding surface with the side weir 2 was examined. The experimental conditions are described in Table 1, and the experimental results are described in Table 2, together with Comparative Examples.

In this experimental example, the sliding surface of the side weir 2 sliding on the heat insulating layer 9 at the protruding end 1t of the cooling drum was formed of a BN ceramic material having a hardness (Hv of 100 g) of 150. The experimental condition and the comparative example are common in the casting conditions, cooling drum dimensions, and side weir conditions.

[Experimental conditions] Cooling drum diameter: 1000 mm Width: 1000 mm

[0032]

[Table 1]

[0033]

[Table 2]

(Experimental Example 1) In Experimental Example 1, as shown in Table 1, the end face of the drum protruding end 1t has a thermal conductivity of 0.1 mm.
A heat insulating layer 9 having a thickness of 10 μm is formed by spraying a SiO ₂ material having a hardness of 1 W / m · K and a thermal expansion coefficient of 1 × 10 ⁻⁶ / ° C. and a hardness (Hv 100 g) of 200 from a Cu alloy. The thickness t of the heat insulating layer 9 and the thermal conductivity λ were set so that the thickness (1 / t) × the thermal conductivity λ = 10000. The wear amount (wear depth) of the sliding surface of the drum protruding end portion 1t with the side weir in this experimental example was 10 μm as shown in Table 2. The growth of the metal between the sliding surfaces of the side weir 2 and the drum protruding end 1t was suppressed.

(Experimental Example 2) In Experimental Example 2, as shown in Table 1, the end face of the drum protruding end portion 1t had a thermal conductivity of 1 W.
/ M · K, a thermal expansion coefficient of 8 × 10 ⁻⁶ / ° C., and a ZrO ₂ material having a hardness of 620 (Hv: 100 g) higher than that of the Cu alloy formed by thermal spraying to form a heat insulating layer 9 having a thickness of 100 μm. The thickness t of the heat insulating layer and the thermal conductivity λ were set so that the thickness (1 / t) × the thermal conductivity λ = 10000. As shown in Table 2, the wear amount (wear depth) of the sliding surface of the drum protruding end portion 1t with the side weir 2 in this experimental example was 5 μm, which was a better value than Experimental Example 1. Further, the growth of the metal between the sliding surfaces of the side weir and the drum protruding end 1t was well suppressed.

(Experimental Example 3) In Experimental Example 3, as shown in Table 1, the thermal conductivity was 1 W at the end face of the drum protruding end 1t.
/ M · K, a coefficient of thermal expansion of 10 × 10 ⁻⁶ / ° C. and higher hardness (Hv 100 g) 400 than Cu alloy 400 ZrO ₂ —CoCr
The thermal insulation layer 9 having a thickness of 500 μm was formed by spraying AlY. The thickness of the thermal insulation layer (1 / t) × thermal conductivity λ = 2
The thickness t of the heat insulating layer and the thermal conductivity λ were set so as to be 000. Side weir 2 at drum protruding end 1t in this experimental example
As shown in Table 2, the wear amount (wear depth) of the sliding surface was 7 μm, which was a better value than that of Experimental Example 1. Further, the growth of the metal between the sliding surfaces of the side weir and the drum protruding end 1t was well suppressed.

(Experimental Example 4) In Experimental Example 4, as shown in Table 1, the end face of the drum protruding end 1t had a thermal conductivity of 2 W
/ M · K, thermal expansion coefficient 13 × 10 ^-6 / ° C, higher hardness than Cu alloy (Hv 100g), 62Al-10Cr of 700
The heat insulating layer 9 having a thickness of 5000 μm is formed by building up -10 Fe-18Co, and the thickness of the heat insulating layer (1/1)
t) × thickness t of the heat insulating layer so that the thermal conductivity λ = 400
And the thermal conductivity λ were set. Abrasion amount (abrasion depth) of the sliding surface of drum protruding end 1t with side weir 2 in this experimental example
Was 3 μm, as shown in Table 2, and showed a better value than Experimental Example 1. Further, the growth of the metal between the sliding surfaces of the side weir and the drum protruding end 1t was well suppressed.

(Experimental Example 5) In Experimental Example 5, as shown in Table 1, the end face of the drum protruding end 1t had a thermal conductivity of 3 W
/ M · K, thermal expansion coefficient 13 × 10 ⁻⁶ / ° C., higher hardness (Hv 100 g) 650 than Cu alloy, 650 Al-Cu-Fe-
The heat insulating layer 9 having a thickness of 10000 μm was formed by overlaying Cr, and the thickness of the heat insulating layer (1 / t) × thermal conductivity λ
= Thickness of thermal insulation layer and thermal conductivity λ such that
It was set. As shown in Table 2, the wear amount (wear depth) of the sliding surface of the drum protruding end 1t with the side weir 2 in Experimental Example 5 was 3 μm. Further, the growth of the metal between the sliding surfaces of the side weir 2 and the drum protruding end 1t was sufficiently suppressed.

(Comparative Example 1) In Comparative Example 1, the drum body 1b and the drum protruding end 1t have a thermal conductivity of 350 W / m.
-K, hardness (Hv 100g) 150, coefficient of thermal expansion 1
A cooling drum integrally formed of a Cu alloy material of 8 × 10 ⁻⁶ / ° C. and having no heat transfer layer, intermediate layer, and heat insulating layer as shown in FIG. 4 was used. The amount of abrasion (abrasion depth) of the end face of the drum protruding end 1t in Comparative Example 1 was 100 μm as shown in Table 2, and a growth tendency of the metal was observed near the side weir.

(Comparative Example 2) In Comparative Example 2, the drum body 1b and the protruding end 1t of the drum had a thermal conductivity of 350 W / m.
-K, hardness (Hv 100g) 150, coefficient of thermal expansion 1
It is formed of a Cu alloy material of 8 × 10 ⁻⁶ / ° C., and has a thermal conductivity of 10 W / m · K and a thermal expansion coefficient of 1 on the end surface of the drum protruding end 1 t.
0 × 10 ⁻⁶ / ° C. higher hardness than Cu alloy (Hv 100
g) A cooling drum as shown in FIG. 5 in which a CoCrAlY of 150 was sprayed to form a coating layer 8 (heat insulating layer 9) having a thickness of 50 μm, and (1 / t) × thermal conductivity λ = 2
Coating layer 8 (heat insulation layer 9) so as to be 00000
Of which the thickness t and the thermal conductivity λ were set. As shown in Table 2, the wear amount (wear depth) of the sliding surface of the drum protruding end portion 1t with the side weir 2 in Comparative Example 2 was 50 μm.
Showed a better value than Comparative Example 1, but showed a larger value than the experimental example of the present invention described above. In addition, there was a tendency for metal to grow near the side weir.

It should be noted that the present invention is not limited to the above-described embodiments and experimental examples, and a twin-drum continuous sheet casting apparatus to which the cooling drum of the present invention is applied is limited to the above-described embodiments. Not something. For example, regarding the cooling structure of the cooling drum and its arrangement, the cooling drum conditions (material, dimensions, and shape of the end face, the material combination of the body and the end, the coating (joining) means, etc., the side weir conditions (structure, dimensions, and shape) , Combination of materials), operating conditions of continuous casting (temperature, speed, size, etc.), etc., and are changed within the scope of the claims of the present invention.

[0042]

According to the present invention, a heat insulating layer made of a material having a low thermal conductivity is formed on the end face of the cooling drum in contact with the side weir and the solidified shell, thereby suppressing wear on the end face and suppressing heat removal. By doing so, the growth of the metal in the vicinity of the side weir can be suppressed, and the shape of the cooling drum can be maintained for a long period of time to realize stable continuous casting.

[Brief description of the drawings]

FIG. 1A is an explanatory side sectional view showing an example of an end structure of a cooling drum to which the present invention is applied, and FIG. 1B is an explanatory side view of FIG.

FIG. 2 is an explanatory side sectional view showing an example of an end structure in the embodiment of the cooling drum of the present invention.

FIG. 3 is an explanatory front view showing a general structural example of a twin-drum continuous thin-plate casting apparatus to which the present invention is applied.

FIG. 4 (a) is a side sectional explanatory view showing an example of a basic structure of a cooling drum end portion used in a standard twin-drum type continuous thin plate casting apparatus, and FIG. 4 (b) is a side view of FIG. FIG.

FIG. 5 is an explanatory side sectional view showing an example of a structure of an end portion of a conventional cooling drum used in a twin-drum thin sheet continuous casting apparatus.

[Explanation of symbols]

1a, 1b Cooling drum 1t Projecting end 1p End face 1s Shaft 2 Side weir 3 Moving mold (pool pool) 4 Tundish 5 Nozzle 6 Molten steel 6s Solidified shell 6c Thin plate (slab) 7 Cooling structure 8 Coating layer 9 Heat insulating layer 10 Intermediate layer 11 Heat transfer layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuto Yamamura 20-1 Shintomi, Futtsu-shi, Chiba Prefecture Nippon Steel Corporation Technology Development Division (72) Inventor Chihiro Yamachi 20-1 Shintomi, Futtsu-shi, Chiba New Nippon Steel Corporation Technology Development Division F-term (reference) 4E004 DA13 NA05 NB07 QA01 QA03

Claims (7)

[Claims] An end face of a cooling drum used in a twin-drum continuous thin-plate casting apparatus having a pair of cooling drums rotating in opposite directions and a pair of side dams pressed on both end surfaces of the cooling drum. Has a thermal conductivity of 10W /
A cooling drum for a twin-drum continuous sheet casting machine, wherein a heat insulating layer of m · K or less is formed. 2. An end face of a cooling drum used in a twin-drum continuous sheet casting apparatus having a pair of cooling drums rotating in opposite directions and a pair of side dams pressed on both end surfaces of the cooling drum. When the thickness of the heat-insulating layer formed as described above is t and the thermal conductivity is λ, the following formula (1 / t) × λ = 10 ² W / m ² · K to 10 ⁴ W / m ²
A cooling drum for a twin-drum continuous sheet casting apparatus, wherein the thickness t and the thermal conductivity λ of the heat insulating layer made of the low thermal conductivity material are set so as to satisfy K 1. 3. A cooling drum used in a twin-drum type continuous casting apparatus having a pair of cooling drums rotating in opposite directions and a pair of side dams pressed on both end surfaces of the cooling drum. 100W thermal conductivity
/ M · K or more, and a thermal insulation layer formed by thermal spraying or overlaying a low thermal conductivity material having a thermal conductivity of 3 W / m · K or less and a thickness of 10 to 10000 μm on the drum end surface. A cooling drum for twin-drum continuous sheet casting equipment. 4. The twin-drum continuous thin plate according to claim 1, wherein the heat-insulating layer formed on the end face of the drum has a hardness at room temperature (Hv of 100 g) of 200 or more. Cooling drum for casting equipment. 5. The ratio of the coefficient of thermal expansion of the heat insulating layer formed on the end face of the drum to the coefficient of thermal expansion of the drum body member is 50 to 120.
%. The cooling drum for a twin-drum continuous thin plate casting apparatus according to claim 1, wherein 6. The outer peripheral surface of the drum body has a thermal conductivity of 30 W.
6. A heat transfer layer having a thickness of 10/5000 [mu] m or more and a thickness of 10/5000 [mu] K or more.
4. A cooling drum for a twin-drum continuous sheet casting apparatus according to claim 1. 7. An intermediate layer having a thermal conductivity of 30 W / m · K or more and a thickness of 10 to 5000 μm is interposed between the drum body member and the heat insulating layer. A cooling drum for a twin-drum continuous sheet casting apparatus according to any one of the preceding claims.