KR101286206B1

KR101286206B1 - Pinch roll of twin roll strip caster

Info

Publication number: KR101286206B1
Application number: KR1020100135930A
Authority: KR
Inventors: 하만진; 송병준; 정성인
Original assignee: 주식회사 포스코
Priority date: 2010-12-27
Filing date: 2010-12-27
Publication date: 2013-07-15
Also published as: KR20120073991A

Abstract

The present invention relates to a pinch roll installed in front of the in-line rolling mill of the twin-roll thin sheet casting apparatus to prevent meandering of the thin plate, the non-contact section that is not in contact with the thin plate is formed at both ends, the remaining portion except the both ends of the thin plate Provided is a pinch roll of a twin roll thin plate casting apparatus, characterized in that a contact section is formed in contact with the sheet.
In the case of applying the pinch roll according to the present invention, even if an edge crack occurs in the edge portion of the thin plate before rolling of the inline rolling mill, a scull is mixed, or a hatch is formed, the thin plate is caught by the pinch roll or the pinch roll passes when the pinch roll passes. It is possible to improve the error rate and casting stability by preventing the plate breakage, which can be caused by the gap of the gap does not change to impact or warp the thin plate.

Description

PINCH ROLL OF TWIN ROLL STRIP CASTER}

The present invention relates to a pinch roll of a twin roll thin sheet casting apparatus, and more particularly, to a pinch roll which is installed in front of an inline rolling mill of a twin roll thin sheet casting apparatus to prevent thinning while guiding a thin plate.

In general, a twin roll sheet metal casting method is a process of continuously supplying a molten steel between a pair of rotating casting rolls and continuously manufacturing a sheet product having a thickness of several mm directly from the molten steel.

As shown in Fig. 1, molten steel is injected and solidified between the casting rolls 1 cooled while rotating in the opposite direction to form a solidified shell, which is pressed in a roll nip to cast a thin plate 2. The thin plate 2 thus cast is guided by the pinch rolls 3 through the root pits and then rolled in the inline rolling mill 4. In the twin roll type sheet casting process, rolling is performed in one stand. This is a very difficult task since the desired final quality has to be achieved, and the rolled hot rolled sheet is wound on the coiler 8 via the sheer pinch roll 5 and the coiler pinch roll 7. do.

In general, a thin sheet drawn and cast between a pair of rolls is very susceptible to impact since it is not a recrystallized structure before rolling, and thus when the cast thin sheet passes through the pinch rolls 3 before rolling the inline rolling mill 4. Many breaks occur.

That is, the pinch rolls 3 installed in front of the inline rolling mill 4 are installed for the purpose of meandering control of the cast thin plate, and press the cast thin plate with a constant load. As described above, the gap between the upper and lower pinch rolls 3 increases when the edge crack 9a occurs in the edge portion in the thin sheet casting process, the edge skull 9b is mixed, or the gush 9c is formed. While the thin plate is caught by the pinch rolls 3, or the impact is applied to the thin plate, or the thin plate is twisted in meander, causing plate breakage, which causes a problem in that the error rate and casting stability of the product are lowered.

The present invention has been made to solve the above problems, by improving the shape of the pinch roll of the twin-roll thin sheet casting apparatus to generate an edge crack, mixed with the scull, or edges in the edge portion of the sheet before rolling of the inline rolling mill Even if formed, the pair can improve the error rate and casting stability by preventing plate breakage, which may be caused by impacting or twisting the sheet due to the pinch roll being not caught by the pinch roll or the gap of the pinch roll being unchanged when passing through the pinch roll. An object of the present invention is to provide a pinch roll of a roll type thin sheet casting device.

In order to achieve the above object, the present invention, in the pinch roll is installed in front of the in-line rolling mill of the twin-roll thin plate casting apparatus to prevent meandering of the thin plate, both ends are formed with a non-contact section that is not in contact with the thin plate, both ends The remaining portion except the contact section is formed in contact with the thin plate, the length (W) of the contact section is smaller than the length (L) of the full width of the thin plate, the width (D) of the non-contact section is 0.1L <D Provided is a pinch roll of a twin roll thin sheet casting apparatus characterized by satisfying < 0.2L.

According to the present invention, when the thin plate passes through the pinch roll, even if edge cracks are generated, sculls are mixed, or dents are formed in the edge portion of the thin plate before rolling of the in-line rolling mill by improving the shape of the pinch roll of the twin-roll thin sheet casting apparatus. It is possible to improve the error rate and casting stability by preventing plate breakage, which may occur due to impact or warpage of the thin plate due to the pinch roll or the gap of the pinch roll does not change.

1 is a schematic view of a typical twin roll sheet metal casting process.
Figure 2 is a view showing a defect occurred in the edge portion of the cast thin plate, (a) is an edge crack, (b) is an edge skull, (c) is a debris.
Figure 3 is a view showing the configuration of the pinch roll in accordance with an embodiment of the present invention.

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

The pinch roll of the twin-roll thin plate casting apparatus according to the present invention has a contact section in contact with the thin plate at the center portion, and forms a non-contact section in contact with the thin plate at both ends thereof, so that an edge crack occurs at the edge portion of the thin plate before rolling, Even if the edge skull is mixed or the back is formed, the thin plate is prevented from breaking due to pinching rolls, impact or warping the thin plate.

When the thin plate 2 before rolling by the in-line rolling mill 4 passes through the pinch roll 3, when the edge crack 9a of FIG. As the gap of the pinch rolls 3 decreases, the pinch rolls 3 are inclined to one side, which causes impact or meandering on the thin plate, causing plate breakage, and the edge skull 9b of FIG. 2 (b) is mixed. In this case, the edge portion in which the edge skull 9b is mixed increases in thickness and the temperature of the thin plate becomes low, while the other edge portion is relatively thin and the temperature of the thin plate becomes high so that the pinch rolls 3 become the edge skull. As it is lifted toward the position of the impact or meandering in the thin plate, if the gush is created in Figure 2 (c) this part also increases the thickness, so the pinch roll (3) is lifted toward the position of the gush Impacts or meandering on the sheet.

Therefore, when the thin plate is meandered with a pinch roll having a width equal to or greater than that of the thin plate as in the related art, impact or meandering occurs in the thin plate due to the edge crack 9a, the edge skull 9b, and the toothing 9c. This is the main cause of breakage of sheet metal.

Therefore, the pinch roll 3 of the twin roll thin sheet casting apparatus according to the present invention is installed in front of the inline rolling mill 4 of the twin roll thin sheet casting apparatus to prevent meandering of the thin plate 2 cast. As shown, a contact section in contact with the thin plate 2 passing through the pinch roll 3 is formed in the center of the pinch roll 3, wherein the length (W) of the contact section is the thin plate 2 It is formed to be smaller than the length (L) of the full width.

In addition, both ends of the pinch roll 3 are formed with a non-contact section, which is a hatched section of FIG. 3, which is not in contact with the thin plate 2.

That is, a section of both ends of the pinch roll 3 which presses the edge portion of the thin plate in which a plurality of edge defects exist, such as the edge crack 9a, the edge scull 9b, and the flap 9c, is used as a non-contact section. By forming the pinch rolls 3 so as not to be in contact with the thin plate 2, it is possible to prevent generation of plate break before rolling.

At this time, since the position where the edge defects occur at both edge portions of the thin plate does not have a large difference, the width D of the non-contact section preferably satisfies 0.1L <D <0.2L.

This is a problem that plate breakage may occur due to edge defects when the width D of the non-contact section is 0.1L or less, and the pinch roll 3 and the thin plate 2 when the width D of the non-contact section is 0.2L or more. This is because the area in contact with) is reduced, so the meander control of the sheet is not easy.

In addition, the height (H) of the non-contact section preferably has a range of 10 times to 20 times the thickness (t) of the thin plate 2, and if H is 10t or less, edge cracks, edge skulls, This is because there is a problem that plate breakage may occur due to edge defects, such as dents, and when H is 10 t or more, it is difficult to control meandering due to weight reduction of the pinch roll.

[Example]

The molten steel of Table 1 was injected between two casting rolls rotating in opposite directions, and the thin plates were cast, and then rolled through an pinch roll (3) to an inline rolling mill (4), and sheared with a sheath (6) to coiler (8) The coil was created by winding in).

At this time, the diameter of the casting roll used was 1,400mm, the width is 1,350mm, made of the same material, the surface is plated with nickel, the inside is cooled by water-cooling, a thin plate of 5mm thickness below the pair of casting rolls After withdrawing, the meandering control was performed by using the pinch rolls 3 formed according to the conditions of Table 1, and the results of the plate breaking through the pinch rolls 3 were observed and the results are shown in Table 1 again. It was.

[Table 1]

As shown in Table 1, the pinch rolls having the length W of the contact section in which the cast thin plates, each of which has edge cracks and edge flaws of the edge skulls, are in contact with the thin plates, are the same as the length L of the entire width of the thin plates, as shown in Table 1, respectively. In the case where A and pinch roll B were used, gaps at both ends of the pinch rolls were different, indicating that plate fracture occurred due to impact or meandering on the thin plate.

On the other hand, since the length (W) of the contact section in contact with the thin plate is smaller than the length (L) of the full width of the thin plate, in the case where there is a non-contact section, even if there is an edge defect in the cast sheet, most of the plate break does not occur, but the non-contact section When the width (D) or the height (H) of the edge was too small and the edge defects were severe, plate breakage occurred occasionally, such as pinch roll C and pinch roll G. This is mainly due to the impact or meandering on the thin plate due to the inclination due to the thickness difference between the two edge portions of the pinch roll due to the edge skull or the thickening rather than the edge crack.

Therefore, in order to prevent the breakage of the thin plate before rolling in the twin-roll thin plate casting process, it is necessary to form a non-contact section which is not in contact with the thin plate at both ends of the pinch roll, and more preferably, the width D of the non-contact section is 0.1L. By controlling the height (H) of the non-contact section in the range of <D <0.2L in the range of 10t <H <20t, even if there are edge defects such as edge cracks, edge sculls, and bristles on the sheet, the plate breaking rate is prevented. And casting stability.

While the invention has been shown and described in connection with specific embodiments so far, it will be appreciated that the invention can be varied in various ways without departing from the spirit or scope of the invention as set forth in the claims below. Those skilled in the art will readily know.

1. Casting roll 2. Lamination
3. Pinch Roll 4. Inline Rolling Mill
5. Resting Pinch Roll 6. Resting
7. Coiler Pinch Roll 8. Coiler
9a. Edge crack 9b. Edge skull
9c. Sickness

Claims

In the pinch roll which is provided in front of the in-line rolling mill of a twin-roll type thin sheet casting apparatus, and prevents meandering of a thin plate,
Non-contact section that is not in contact with the thin plate is formed at both ends,
The remaining portion except for both ends is formed in contact with the thin plate,
The length (W) of the contact section is smaller than the length (L) of the full width of the thin plate,
The pinch roll of the twin-roll thin-plate casting apparatus, characterized in that the width (D) of the non-contact section satisfies 0.1L <D <0.2L.

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