JP7460901B2 - Segment roll with sleeve for conveying slabs in continuous casting - Google Patents

Description

The present invention relates to a sleeved segment roll for conveying slabs in continuous casting.

In continuous casting for steelmaking, segment rolls (hereinafter referred to as segment rolls) used to transport slabs downstream of the mold can bend due to thermal deformation, which can cause thermal cracks on the surface of the segment roll when the machine is stopped due to thermal stress caused by heat bias from the transported slab to the segment roll. After restarting the operation, the segment roll bent due to thermal deformation is repeatedly straightened due to its own rotation and the weight of the transported slab, which can cause the cracks to progress in the circumferential and radial directions, eventually resulting in the breakage of the segment roll. For this reason, as described in Patent Document 1, many measures have been taken regarding the segment roll structure, such as sleeves to prevent breakage and embedding particles to prevent crack progression.

Japanese Patent Application Publication No. 59-137170

However, because segment rolls are subject to large thermal loads and thermal deformation, continued use of the sleeve can cause the cracks to grow and eventually lead to breakage.

The present invention was made against this background, and the problem that the present invention aims to solve is to prevent crack growth due to thermal deformation of the segment roll and suppress a decrease in its lifespan.

To solve the above problem, a sleeve-equipped segment roll for transporting cast pieces in continuous casting is provided, which is characterized in that the roll body and the sleeve are fitted to the outer periphery of the roll body, and the roll body and the sleeve are fixed together by an anti-rotation key made of fiber-reinforced ceramics.

Further, the sleeve may be composed of a plurality of ring-shaped members, and it is preferable that the sleeve has a slit-shaped groove extending in the circumferential direction of the roll.

Further, the sleeve may include a plurality of ring-shaped members, and a spacer made of fiber-reinforced ceramics may be arranged between the plurality of ring-shaped members to form the slit-shaped groove. preferable.

Further, it is preferable that a layer made of fiber-reinforced ceramics be provided between the roll body and the sleeve at a location offset in the roll circumferential direction with respect to the rotation prevention key.

By using the present invention, it is possible to avoid crack growth due to thermal deformation of the segment roll, and it is possible to suppress a decrease in life.

It is a side view of an example of a continuous casting machine. However, a partially enlarged view of a segment roll used in a continuous casting machine is also shown. FIG. 2 is an exploded perspective view of an example of a sleeve-equipped segment roll for transporting a cast strip in the continuous casting according to the embodiment. FIG. 3 is a sectional view of the segment roll in FIG. 2 in the circumferential direction and the trunk length direction. FIG. 2 is a longitudinal cross-sectional view of a segment roll with a sleeve for conveying slabs when a sleeve divided into ring shapes is used. 13 is a diagram showing an example in which a slit-shaped groove portion is provided by creating a portion in a cylindrical sleeve whose radial length is partially shortened. FIG. For a ring-shaped member that forms a sleeve by stacking multiple rings, by creating a portion with a partially short radial length adjacent to another ring-shaped member, when stacking the ring-shaped members, the sleeve It is a figure showing the example which provided the slit-like groove part in the. 13 is a diagram showing an example of a sleeve having a plurality of ring-shaped members, in which a slit-forming spacer is disposed between the ring-shaped members to provide a slit-shaped groove portion. FIG. A circumferential cross-sectional view of an example in which a layer made of fiber-reinforced ceramics is provided between the roll body and the sleeve and circumferentially offset from the rotation prevention key, and a body length direction A- for the cross-sectional view. It is an A' sectional view.

The following is an embodiment of the invention. As can be seen from Figs. 2 and 3, the sleeved segment roll 1 of this embodiment includes a roll body 2 and a sleeve 3 located on the outer periphery of the roll body 2, and the roll body 2 and the sleeve 3 are fixed by an anti-rotation key 4 made of fiber-reinforced ceramics (CMC: Ceramic Matrix Composite). Fiber-reinforced ceramics have high high-temperature strength and are less susceptible to crack propagation, making them suitable for fixing the sleeve 3 to the roll body 2. In addition, one or multiple short anti-rotation keys 4 are arranged in the keyway 19. When there is one anti-rotation key 4, it is preferable that it is long in the barrel length direction of the sleeved segment roll 1 and extends almost the entire length of the keyway 19 excluding the portion of the holding member 6. The same applies when multiple short anti-rotation keys are arranged.

As can be seen from FIG. 2, in this embodiment, the anti-rotation key 4 is arranged so as to be sandwiched between the pressing members 6 provided on both ends of the cylindrical roll body 2. In other words, the anti-rotation key 4 is arranged so as to be surrounded by the roll body 2, the sleeve 3, and the pressing members 6. This makes it possible to prevent early deterioration of fiber-reinforced ceramics, which are expensive but prone to oxidation and thinning.

Further, the restraining members 6 of the embodiment are inserted into the slits 19 provided in the sleeve 3 and the roll body 2 in the same way as the rotation prevention key 4; 2 is preferably welded.

Moreover, the sleeved segment roll 1 of the embodiment is provided with a through hole 29 around its rotation center. Since the through holes 29 are used to pass cooling water or the like, it is possible to suppress the sleeved segment roll 1 from increasing in temperature.

With the present invention, even if cracks occur in the circumferential direction on the surface of the sleeve 3 and propagate in the radial direction due to the influence of the ambient temperature, the temperature of the slab, the impact of conveying the slab, etc., the sleeve 3 will remain intact. Since the boundary portion of the rotation prevention key 4 and the boundary portion between the sleeve 3 and the roll body 2 are discontinuous, the propagation of cracks to the rotation prevention key 4 or the roll body 2 is suppressed. Therefore, even if thermal cracks occur, they do not propagate to the roll body 2, so that it is possible to suppress shortening of the life of the sleeved segment roll 1.

For ease of installation of the sleeve 3 and to extend its lifespan by replacing only the cracked portion, it is preferable to fit the sleeve 36, which is divided into a ring shape, onto the roll body 2 as shown in Figure 4, and fix it to the roll body 2 using an anti-rotation key 4 so that they rotate together.

Since the surface of the sleeve 3 is greatly affected by the heat from the cast piece, it is preferable to provide the sleeve 3 with circumferentially extending slit-shaped grooves 31 as shown in FIG. 5. In this way, when the sleeve 3 is heated, it can expand in the barrel length direction, and the occurrence and expansion of cracks in the sleeve 3 can be suppressed. There are no particular limitations on the method of providing the slit-shaped grooves 31, but the slit-shaped grooves 31 may be provided by creating a portion of a single cylindrical sleeve 3 that is partially shorter in radial length.

When using a sleeve 36 divided into ring shapes, as shown in FIG. 6, the ring-shaped members 36 that form the sleeve 3 by stacking multiple members may be provided with a portion that is partially shorter in radial length at a location adjacent to another ring-shaped member 36, so that a slit-shaped groove portion 31 can be provided in the sleeve 3 when the ring-shaped members 36 are stacked.

Further, as can be understood from FIG. 7, regarding the sleeve 3 including a plurality of ring-shaped members 37, the slit-forming spacer 38 is arranged between the ring-shaped members 37 to provide the slit-shaped groove portion 31. It's okay. In this case, the slit-forming spacer 38 may be made of metal, but is preferably made of fiber-reinforced ceramics.

However, over time, cracks that have entered the surface of the sleeve 3 will progress toward the rotation axis of the sleeved segment roll 1. Because the roll body 2 and sleeve 3 are made of metal, it is possible that a crack that has progressed from the sleeve 3 will propagate to the roll body 2. Therefore, in the example shown in Figure 8, a layer 5 made of fiber-reinforced ceramics is provided between the roll body 2 and sleeve 3, at a location circumferentially offset from the anti-rotation key 4.

In this case, the layer 5 made of fiber-reinforced ceramics is preferably at least as long as the portion of the sleeve 3 that contacts the cast piece in the axial direction. In addition, it is preferably provided over the entire circumferential direction of the roll body 2 in the axial direction. However, taking into account the strength of the sleeve 3, the layers 5 may be thinned out. In this case, multiple members may be provided between the roll body 2 and the sleeve 3, or a member with a partial space may be provided between the roll body 2 and the sleeve 3.

It is preferable that the fiber-reinforced ceramic has better thermal conductivity than the roll body 2, and specifically, SiC or a material mainly composed of SiC is preferable.

Although the present invention has been described above, focusing on the embodiments, the present invention is not limited to the above embodiments, and can be modified in various ways.

1 Segment roll with sleeve 2 Roll body 3 Sleeve 4 Anti-rotation key 5 Layer 31 Slit-shaped groove 37 Ring-shaped member 38 Spacer

Claims (5)

A sleeve is fitted to the outer periphery of the roll body,
A sleeved segment roll for transporting cast pieces in continuous casting, characterized in that the roll body and the sleeve are fixed together by an anti-rotation key made of fiber-reinforced ceramics. A sleeved segment roll for transporting cast pieces in continuous casting, as described in claim 1, characterized in that the sleeve is composed of multiple ring-shaped members. The sleeve-equipped segment roll for transporting cast pieces in continuous casting according to claim 1 or 2, characterized in that the sleeve is formed with a slit-shaped groove extending in the circumferential direction of the roll. The sleeve is composed of a plurality of ring-shaped members,
3. The segment roll with sleeve for transporting cast pieces in continuous casting as claimed in claim 2, characterized in that a spacer made of fiber-reinforced ceramic is arranged between the plurality of ring-shaped members to form the slit-shaped groove portion. A segment roll with a sleeve for transporting cast pieces in continuous casting as described in any one of claims 1 to 4, characterized in that a layer made of fiber-reinforced ceramics is provided between the roll body and the sleeve at a location offset in the circumferential direction of the roll with respect to the anti-rotation key.