KR100544613B1 - An apparatus for removing the black layer on surface of roll in twin roll strip caster - Google Patents

Abstract

The present invention relates to an apparatus for removing black skin adhering to the outer circumferential surface of a casting roll in a casting machine for casting a thin plate in a twin roll manner.

In the present invention, a brush is in contact with the upper and lower outer peripheral surfaces of the casting rolls (2) and (2a), and a plurality of upper and lower brush rolls (31) and (32) are disposed in the longitudinal direction of the casting rolls (2) and (2a). A first brush part (30) for uniformly brushing the inner upper and lower surfaces of the dimple (22) formed on the casting roll (2) (2a) surface by rotating (33) and (34) in opposite directions; Brush 41a, 42a, 43a, 44a abuts on the outer circumferential surface of the casting roll 2, 2a, is assembled to a roll shaft perpendicular to the roll shaft of the casting roll 2, 2a, and A plurality of upper and lower cross brush rolls 41, 42, 43, 44 mounted at a predetermined interval in the longitudinal direction of the casting rolls 2 and 2a are disposed on the upper and lower brush rolls 31 and 32. And a second brush portion 40 which rotates in different directions between the 33 and 34 to uniformly brush the inner, left and right surfaces of the dimple 22 formed on the casting rolls 2 and 2a. When the molten steel is solidified in contact with the surface of the roll, fine cracks are formed on the surface of the cast slab that is cast by brushing the surface of the casting roll in various directions so as to uniformly solidify in all directions.

Sheet casting machine, upper and lower brush roll, upper and lower cross brush roll, black skin, dimple

Description

AN APPARATUS FOR REMOVING THE BLACK LAYER ON SURFACE OF ROLL IN TWIN ROLL STRIP CASTER}

1 is a schematic view showing a typical twin roll sheet casting machine,

Figure 2 is a detailed view showing the roughness state of the roll surface in a general twin roll sheet caster,

Figure 3 is a working state to remove the black skin of the roll surface as a brush roll in a general twin roll sheet caster,

4 is an enlarged view of the cast steel showing the occurrence of minute cracks on the surface of the cast steel,

5 is a state diagram in which the casting roll surface black skin removal apparatus is installed in a twin roll thin caster according to the present invention,

Figure 6 is a perspective view showing a cast roll surface black skin removal device in a twin-roll sheet caster according to the present invention,

Figure 7 is a schematic diagram showing an operating unit for driving the upper and lower cross brush rolls employed in the cast roll surface black skin removal device in a twin roll sheet caster according to the present invention.

Explanation of symbols on the main parts of the drawings

2,2a ... casting roll 4 ..... edge dam

31,33 ... upper brush roll 32,34 ... lower brush roll

41,43 ... upper cross brush roll 42,44 ... lower cross brush roll

45,46 ... upper and lower roll support 47,48 ... upper and lower motor

47a, 48a ... chain member 100 ... sheet casting machine

The present invention relates to an apparatus for removing black skin adhering to the outer circumferential surface of a casting roll in a twin roll casting machine, and more particularly, the black skin accumulated on rough dimples of the roll surface during casting is almost completely removed in all directions. In the twin roll type sheet casting machine which prevents the occurrence of minute cracks in the cast surface by brushing the surface of the casting roll in various directions so as to allow uniform solidification in all directions when the molten steel is solidified while contacting on the roll surface. The present invention relates to a casting roll surface black skin removal device.

In general, the twin-roll sheet caster 100, as shown in Figure 1, the immersion nozzle (9a) from the tundish (9), which is a container that stores the molten steel between the two rotating casting rolls (2) (2a) The molten steel is supplied through the molten steel, and the molten steel pool 8 is formed as the supplied molten steel, and the molten steel of the molten steel pool 8 is in contact with the outer circumferential surface of the casting rolls 2 and 2a to form a solidification ability. (2) As the 2a rotates, it meets at the roll nearest point to form the slab 5.

In the twin roll type sheet casting process, in order to prevent the molten steel from leaking to the barrel side of the casting rolls (2) and (2a), edge dams (4) serving as dams are provided, respectively, on the upper parts of the casting rolls (2) and (2a). In order to prevent the molten steel from being oxidized, the meniscus shield 6 is mounted to seal the supplied inert gas to provide a closed space on top of the casting rolls 2 and 2a.

Accordingly, in the closed space as described above to prevent the oxidation of the molten steel serves to suppress the occurrence of the cast iron surface defects caused by the inflow of various inclusions and oxidative impurities during casting.

In the case of thin casting, unlike the conventional continuous casting, since the mold flux is not used in the mold during casting, molten steel is easily vaporized and vaporized, and some of the metal is deposited on the surface of the roll in the form of a single metal. In addition, these deposits act as a thermal resistance and interfere with solidification of the molten steel.

That is, deposits deposited on the outer circumferential surface of the casting rolls 2 and 2a prevent the solidification of molten steel during the casting process, resulting in uneven solidification and generating fine cracks in the uneven solidified portion. Cracks have become a major problem of deteriorating cast quality.

Therefore, in the process of casting a conventional thin plate, in order to remove such deposits deposited and deposited on the surface of the casting rolls (2) and (2a), a plurality of brushes 25a made of iron are mounted on the entire outer circumferential surface of the roll. (25) in the vicinity of the outer circumference of the casting roll (2) (2a), and the casting roll (2) in a state in which the brush 25a of the outer circumference is in contact with the surface of the casting roll (2) (2a) By rotating while applying a constant pressure in the rotational direction as in (2a), a method of dropping the deposit attached to the surface of the casting roll (2) (2a) was adopted.

That is, conventionally, by rotating the brush roll 25 equipped with a brush 25a, in which iron or stainless steel wires are embedded in the outer circumferential surface of the roll member, a method of forcibly brushing off the film deposited on the roll surface in one direction is used. It was.

However, in the conventional method, as illustrated in FIGS. 2 and 3, the enlarged dimples 22 have a hemispherical concave shape, and the black skin 23 is stacked inside the concave dimples 22. Therefore, the brush 25a of the brush roll 25 rotated in one direction cleans only one side of the dimple 2, and the other side of the brush roll 25 is left without the black skin removed.

As such, in the dimples 22 of the casting rolls 2 (2a) brushed by the brush rolls 25 rotated in one direction only, the black skin 23 not removed on one side thereof is left as it is. When the surface of the casting roll (2) (2a) is brought into contact with the molten steel to start solidification, the dimple 22 of the clean surface cleaned by the brush roll 25 and the contaminated surface of the dimple 22 in which black skin remains are left. The thickness of the gas gap forming film is different from each other, thereby causing local tensile stress due to coagulation unevenness, and when the high temperature strength of the coagulation angle is not higher than this, the coagulation angle bursts to generate fine cracks.

Figure 4 shows that the fine cracks are generated on the surface of the slab by the conventional coagulation unevenness, it can be confirmed that the microcracks of several hundred micrometers size occurs on the surface of the slab.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, the object of which is to remove the black roll accumulated in the dimples of the casting roll surface during casting in all directions in all directions up, down, left and right The present invention is to provide a casting roll surface black skin removal device in a twin roll sheet casting machine that can prevent the occurrence of minute cracks on the surface of a cast steel when brushed and solidified while contacting molten steel on the cast roll surface.

As a technical configuration for achieving the above object, the present invention

Apparatus for casting a cast steel having a casting roll that rotates in different directions, an edge dam installed at both ends of the casting roll to form a molten steel pool, and a manikus shield that blocks the upper portion of the molten steel pool to prevent oxidation To

Brushes are in contact with the upper and lower outer peripheral surfaces of the casting roll, and a plurality of upper and lower brush rolls disposed in the longitudinal direction of the casting roll are rotated in opposite directions to uniformly form the inner upper and lower surfaces of the dimple formed on the casting roll surface. A first brush portion for brushing;

Brushes are in contact with the outer circumferential surface of the casting roll, assembled on a roll shaft perpendicular to the roll shaft of the casting roll, and the upper and lower cross brush rolls are mounted in a plurality in the longitudinal direction of the casting roll at a predetermined interval. The present invention provides a casting roll surface black skin removing device in a twin roll thin plate casting machine, comprising: a second brush portion for uniformly brushing the inner, left and right surfaces of the dimple formed on the casting roll surface by rotating in different directions between the brush rolls. By

Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 5 is a state diagram in which a casting roll surface black skin removing device is installed in a twin roll thin casting machine according to the present invention, and FIG. 6 is a perspective view showing a casting roll surface black skin removing device in a twin roll thin casting machine according to the present invention. Is a schematic diagram showing an operation unit for driving the upper and lower cross brush rolls employed in the cast roll surface black skin removal device in a twin roll sheet caster according to the present invention.

As shown in Figs. 5 to 7, the apparatus 1 of the present invention forwards the black skin 23 attached to the inner surface to the dimples 22 formed on the surface of the casting rolls 2 and 2a during the sheet casting process. That is, by brushing evenly in the up, down, left, and right directions, when the molten steel and the casting roll (2) (2a) are in contact with each other, the solidification non-uniformity can be suppressed in the slab width direction to prevent the occurrence of minute cracks on the surface of the slab (5). As such, this device 1 is composed of a first brush portion 30 and a second brush portion 40.

That is, the first brush part 30 is the casting roll so that the outer peripheral surface of the casting roll (2) (2a) and the end portions of the brushes (31a) (32a) (33a) (34a) in parallel with the roll length direction (2) The upper and lower brush rolls 31, 32, 33 and 34 are disposed in the vicinity of the upper and lower outer peripheries of (2a), respectively, and the upper and lower brush rolls 31 and 32 are provided. The roll shafts of (33) and (34) are arranged in parallel with the roll shafts of the casting rolls (2) and (2a).

The upper brush rolls 31 and 33 and the lower brush rolls 32 and 34 brush the inner upper and lower surfaces of the dimples 22 formed on the surfaces of the casting rolls 2 and 2a evenly. The upper side and the lower side are rotated in different rotation directions to remove the black skin attached to the inner surface of the dimple 22 up and down.

Here, the upper brush rolls 31 and 33 are rotated in the same positive direction (+) as in the positive direction (+) of the casting rolls 2 and 2a corresponding to one-to-one, so that the brushes 31a and 33a and the roll outer peripheral surface A large friction force is generated in the tangent line, and the lower brush roll 32 is rotated in the reverse direction (-) with respect to the positive direction (+) of the casting rolls 2 (2a) corresponding to each other one-to-one, so that the brush (32a) ( A small frictional force is generated at the tangential line between 34a) and the outer circumferential surface of the roll.

In addition, the upper and lower brush rolls 31, 32, 33, and 34 are formed at the circumferential line of the brushes 31a, 32a, 33a, 34a, which the casting rolls 2, 2a are in contact with. It is preferable to rotate the drive faster than the rotational speed of the casting rolls 2 and 2a so as to generate a large friction force.

That is, the upper brush rolls 31 and 33 are 10mpm compared with the rotational speed of the casting rolls 2 and 2a, and the lower brush rolls 32 and 34 are formed of the casting rolls 2 and 2a. It is driven at a rotational speed of 20mpm or more compared to the rotational speed to increase the friction on the roll surface to increase the cleaning efficiency by brushing on the roll surface.

In addition, the second brush part 40 is between the upper and lower brush rolls 31 and 32 installed for each of the casting rolls 2 and 2a, and between the other upper and lower brushes 33 and 34. A plurality of upper and lower cross brush rolls 41, 42, 43 and 44 disposed to contact the brushes 41a, 42a, 43a and 44a on the outer circumferential surfaces of the casting rolls 2 and 2a. The upper and lower cross brush rolls (41) (42) (43) (44) are assembled to a plurality of roll shafts perpendicularly intersecting with the roll shafts of the casting rolls (2) (2a), and the casting A plurality of rolls 2 and 2a are mounted at a predetermined interval in the longitudinal direction, and the upper cross brush rolls 41 and 43 and the lower cross brush rolls 42 and 44 are rotated in different directions. Accordingly, the inner left and right surfaces of the dimples 22 formed on the surfaces of the casting rolls 2 and 2a are uniformly brushed so that they are not removed from the upper and lower brush rolls 31, 32, 33 and 34. Unexplained black skin 23 can be completely removed.

Here, the upper and lower cross brush rolls (41, 42, 43, 44) is the 'c' shaped upper and lower roll support 45 is arranged side by side in the longitudinal direction of the casting roll (2) (2a). Driven sprockets 47b and 48b rotatably supported by the roller 46 and mounted on the respective roll shafts are driven by the sprockets of the upper and lower motors 47 and 48 via the chain members 47a and 48a. 47c) and 48c are configured to transmit rotational driving force to the upper and lower cross brush rolls 41, 42, 43 and 44, respectively.

The operation of the present invention having the configuration as described above will be described.

In the state in which the apparatus 1 of the present invention is disposed so that each brush is in contact with the outer circumferential surface of the casting rolls 2 and 2a, the casting rolls 2 and 2a are rotated in the casting direction where they are engaged with each other. During casting, the roll surface of the upper brush rolls 31 and 33 disposed on the upper outer circumferential surface of the casting rolls 2 and 2a is rotated in the same positive direction as the corresponding casting rolls 2 and 2a. Remove the black skin attached to the inner surface of the dimple 22 formed in the.

Then, the lower brush rolls 32 and 34 on the lower outer circumferential surface of the casting rolls 2 and 2a are rotated in the reverse direction with respect to the positive (+) rotation of the corresponding casting rolls 2 and 2a. Therefore, the black skin in the remaining dimples 22 that are not removed because the brushes 31a and 33a of the upper brush rolls 31 and 33 do not reach. Accordingly, the black skin 23 attached to the dimple 22 during the casting operation has a lower side surface of the dimple 22 by the upper brush rolls 31 and 33 on the lower brush rolls 32 and 34. The upper side is cleaned by.

Meanwhile, the black skin 23 attached to the left and right inner surfaces of the dimples 22 that cannot be removed even by the upper and lower brush rolls 31, 32, 33, and 34 is upper and lower cross brush rolls 41. 42) 43) 44).

That is, between the upper and lower brush rolls 31 and 32 and another upper and lower brush rolls 33 and 34, respectively, a pair of upper and lower pairs of upper and lower cross brush rolls 41 and 42 and another While the upper and lower cross brush rolls 43 and 44 are installed, the upper and lower brush rolls 31, 32, 33 and 34 are rotated to drive the upper and lower parts of the dimple in the circumferential direction. The upper cross brush rolls 41 and 43 receive rotational driving force of the upper motor 47 and are simultaneously driven in one direction at the same time on the upper roll support 45, and the lower cross brush rolls 42 and 44 are Since the rotational driving force of the lower motor 48 is transmitted and rotated in the opposite direction at the same time in the lower support 46, it is possible to uniformly remove the black skin on the left and right sides in the dimple 22.

At this time, since the upper brush rolls 31 and 33 rotate in the same positive direction (+) as the casting rolls 2 and 2a, even if only a slight rotation is applied, the actual rotating frictional force is very large, and the lower brush roll 32 (34) rotates in the reverse direction (-), so the actual frictional force is small, and in particular, the black skin on the opposite side where the lower brush rolls 32 and 34 cannot be removed by the upper brush rolls 31 and 33. 23) in order to remove the casting rolls (2) and (2a) to rotate faster than the rotational speed enough to ensure that the black brush is removed by the upper brush rolls (31) 33 in the same condition Consideration should be given.

Thus, by removing the black skin 23 of the dimple 22 formed on the outer circumferential surface of the casting rolls 2 and 2a uniformly in all directions, up, down, left, and right directions, it is possible to completely prevent fine cracks generated in the cast slab.

Further, as a result of removing the black skin 23 on the roll surface during the casting operation by arranging the apparatus 1 of the present invention so that the brush is in contact with the casting rolls 2 and 2a, the upper brush roll 31 is obtained as shown in Table 1 below. (33) is sufficient to remove the black skin even given a slight rotational speed, the lower brush roll 32, 34 was not able to act as a black skin removal only at a speed much faster than the speed of the casting roll. However, even when the upper and lower brush rolls were operated under sufficient conditions, a small amount of fine cracks were generated. In addition, the upper and lower cross brush rolls 41, 42, 43, and 44 were rotated at a speed of 10 mpm or more. As a result, it was possible to prepare a cast steel in which microcracks were completely removed from the surface of the cast steel.

Casting Roll Rotation Speed (m / min) Upper brush roll rotation speed (m / min) Lower brush roll speed (m / min) Top and bottom cross brush roll operation (10mpm or more) Fine cracking degree One +20 0 (20) <+20 (<0) × Large amount (grade 5) 2 +20 -5 (25) +20 (0) × Large amount (grade 4) 3 +20 -10 (30) +20 (0) × Small amount (third class) 4 +20 -10 (30) +40 (-20) × Small amount (class 2) 5 +20 -10 (30) +50 (-30) × Trace amount (grade 1) 6 +20 -10 (30) +50 (-30) ◎ Outbreak nothing (0 grade)

According to the present invention as described above, when the thin plate casting in the sheet casting machine, the black skin deposited on the roll surface by the upper, lower brush roll and the upper and lower cross brush rolls disposed on the outer circumferential surface of the casting roll, By completely removing not only the lower part but also the left and right in the axial direction, and removing the black skin in the dimple from all directions, it is possible to prevent the occurrence of minute cracks on the surface of the cast steel by suppressing the solidification unevenness in contact with the molten steel and the roll surface. In the case of STS 304 steel, it is possible to prevent the fine cracks, which is the most important item of the surface quality of the cast steel, to achieve the production of thin cast steel and good cold rolled products made of the same.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to clarify that knowledge is easy to know.

Claims (5)

To prevent casting rolls 2 and 2a which rotate in different directions, and edge dams 4 and 2 provided at left and right ends of the casting rolls 2 and 2a to form the molten steel pool 8, respectively. In the apparatus for casting the slab (5) having a manifold shield (6) blocking the upper portion of the molten steel pool (8), Brushes 31a, 32a, 33a, 34a abut on upper and lower outer peripheral surfaces of the casting rolls 2, 2a, and a plurality of images disposed in the longitudinal direction of the casting rolls 2, 2a, A first brush for uniformly brushing the inner upper and lower surfaces of the dimples 22 formed on the casting rolls 2, 2a by rotating the lower brush rolls 31, 32, 33, 34 in opposite directions. Brush portion 30; Brushes 41a, 42a, 43a, 44a abut on the outer circumferential surfaces of the casting rolls 2, 2a, and are assembled to a roll shaft that intersects at right angles with the roll shaft of the casting rolls 2, 2a. A plurality of upper and lower cross brush rolls 41, 42, 43 and 44 mounted at a predetermined interval in the longitudinal direction of the casting rolls 2 and 2a are disposed on the upper and lower brush rolls 31 and 32. And a second brush portion 40 for uniformly brushing the inner, left and right surfaces of the dimples 22 formed on the casting rolls 2 and 2a by rotating in different directions between the 33 and 34 portions. Casting roll surface black skin removal device in a twin-roll sheet caster, characterized in that. The method of claim 1, The upper brush rolls 31 and 33 are rotated in the same positive direction (+) as in the positive direction (+) of the casting rolls 2 and 2a corresponding to one-to-one, so that the brushes 31a and 33a are in contact with the outer circumferential surface of the roll. In the circumferential line generates a large friction force, the lower brush roll 32 is rotated in the reverse direction (-) with respect to the positive direction (+) of the casting rolls (2) (2a) corresponding to one-to-one in a twin roll type sheet casting machine Casting roll surface black skin removal device. The method of claim 2, The upper brush rolls 31 and 33 are 10mpm compared to the rotational speed of the casting rolls 2 and 2a, and the lower brush rolls 32 and 34 are rotational speeds of the casting rolls 2 and 2a. Compared to the cast roll surface black skin removal device in a twin roll sheet caster, characterized in that it is driven at a rotation speed of 20mpm or more compared to the above. The method of claim 1, The upper and lower cross brush rolls 41, 42, 43 and 44 are 'c' shaped upper and lower roll supports 45 arranged side by side in the longitudinal direction of the casting rolls 2 and 2a. The driven sprockets 47b and 48b rotatably supported by 46 and mounted on each roll shaft are driven by sprockets 47c of the upper and lower motors 47 and 48 via the chain members 47a and 48a. Casting roll surface black skin removal device in a twin-roll sheet caster, characterized in that the connection to (48c). The method of claim 4, wherein The upper and lower cross brush rolls (41) (42) (43) (44) is cast roll surface black skin removal apparatus in a twin roll sheet caster, characterized in that rotated at a speed of more than 10mpm in different rotation directions.

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