JP2005138137A - Cooling roller for strip caster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling roller for a twin-roll type strip caster, which can prevent generation of chatter. <P>SOLUTION: A cooling roller 1a is formed as follows: on the outer peripheral surface of the roller, a large number of projections 12 for dispersing the starting points of solidification of molten metal are provided at a required pitch; and, for every required numbers of the projections 12, solidification-center forming projections 13, which extract heat from the molten metal more efficiently than the projections 12, are provided. The solidification-center forming projections 13 are disposed in a way that the directions of each sides and diagonal lines of the minimum parallelogram formed by the solidification-center forming projections 13 are shifted at required angles from a roller shaft direction S, so that the solidification-center forming projections 13 are not mutually aligned in the roller shaft direction S. Lens-shaped solids are formed when solidifying the molten metal on the surface part of the cooling roller 1a. Each of the solids is grown so as to be centered on a contact part of the molten metal and the solidification-center forming projection 13, so that each of lens-shaped solids are made not to be aligned in the roller shaft direction S. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cooling roll for use in a twin-roll strip caster.

  Strip casting is known as one of the methods for manufacturing a thin metal plate. A twin roll type strip caster (continuous casting apparatus) developed as such a strip casting has a pair of left and right cooling rolls 1 arranged in parallel in the horizontal direction as shown in FIG. Are provided so as to be able to be driven to rotate in directions facing each other in a state in which a required load (rolling force) is applied in a direction to be pressed by a repulsive force such as a side weir. 2 is placed in contact with the cooling roll 1, and hot metal 3 is poured into a wedge-shaped gap formed between the pair of cooling rolls 1. The solidified metal is rapidly solidified by cooling on the surface, and the solidified metal is pressure-bonded between the roll gaps of the pair of cooling rolls 1 to produce a strip (thin plate) 4. It is obtained by the. In this method, since a thin metal plate can be produced directly from the raw metal hot water 3, the hot rolling process can be omitted and the thin plate production process can be greatly simplified. Therefore, energy saving and production cost reduction can be achieved. It is known as an effect that can be expected.

  By the way, the cooling roll 1 used in the above-described twin-roll type strip caster was initially designed so that the surface in contact with the hot water becomes a smooth surface with very small irregularities. When contacting the surface of the cooling roll 1, the entire surface of the cooling roll 1 is cooled at a time, so that the heat removal of the hot water 3 occurs abruptly and is formed between the cooling rolls 1. In the thin plate 4, there is a problem that the solidification strain of the surface portion becomes large.

  For this purpose, as a countermeasure for reducing the surface distortion of the thin plate 4 produced by relaxing the rapid heat removal when the raw material alloy hot water 3 is solidified, many irregularities are formed on the surface of the cooling roll 1. When the hot water 3 of the raw material alloy is brought into contact with the cooling roll 1, the hot water 3 is brought into contact only with the convex portion on the surface of the cooling roll 1 and is not brought into contact with the concave portion due to surface tension. A gap is formed between the surface of the hot water 3 in the concave portion, and heat transfer from the hot water 3 to the cooling roll 1 is suppressed by the air layer present in the gap, thereby suppressing heat removal from the hot water 3. It has been proposed that the hot water 3 be solidified in a state where it is dispersed from a large number of locations in contact with the convex portions on the surface of the cooling roll 1.

  As the surface structure of the cooling roll 1 based on this idea, for example, as shown in FIGS. 7 (a), (b), (c), (d), and (e), a large number of grooves 6 are formed on the outer peripheral surface of the cooling roll 1. Divided rhombuses, rectangles, triangles, hexagons, circular projections 5 and spirals divided by a number of grooves 8 extending in the spiral direction at a required angle with respect to the axial direction as shown in FIG. A plurality of convex portions 7 extending in the direction (for example, refer to Patent Document 1), or irregularities are formed on the outer peripheral surface of the cooling roll 1 by sandblasting or the like to make the surface of the cooling roll 1 a required rough surface. (For example, refer to Patent Document 2) and the like have been proposed.

Japanese Patent Laid-Open No. 2-165849 Japanese Patent No. 2733776

  However, in the above-described twin-roll strip caster, during operation, each cooling roll 1 swings with a required amplitude in the roll gap direction at a period of about 50 to 100 Hz, so that the roll gap is suddenly changed and opened and closed. As a result, a so-called chatter in which the thickness in the longitudinal direction of the manufactured thin plate 4 changes to form a step sometimes occurs. When such a chatter is generated, the manufactured thin plate 4 has a problem that unevenness occurs at a required pitch in the longitudinal direction and the thickness is not uniform. Furthermore, since the manufactured thin plate 4 may be broken, it is desired to prevent the occurrence of the chatter.

  As one of the methods for preventing the occurrence of such chatter, the reduction force applied in the direction in which the pair of left and right cooling rolls 1 are pressed is lowered, and vibrations in the gap direction are generated in the respective cooling rolls 1. Even if it occurs, it is possible to prevent the vibration from continuing. However, excessively reducing the rolling force of each cooling roll 1 leads to insufficient solidification of the hot water 3, so it is difficult to sufficiently reduce the rolling force of both rolls 1.

  Therefore, the actual situation is that no effective countermeasure for preventing the occurrence of chatter has been proposed yet.

  Accordingly, as a result of repeated efforts and research to prevent the occurrence of chatter during operation of a twin-roll strip caster, the present inventors have found that chatter is generated by the following mechanism. It has become clear that.

  That is, in a strip caster provided with a pair of cooling rolls 1 in which convex portions 9 having a required shape are formed on the outer peripheral surface of the roll, first, the raw material alloy hot water 3 is wedge-shaped between the pair of cooling rolls 1. When the hot water 3 comes into contact with the tops of the convex portions 9 provided on the outer peripheral surface of the cooling rolls 1, the hot water 3 comes into contact with the convex portions 9 as shown in FIG. Coagulation starts from the surface of the part. At this time, the solidification of the hot water 3 progresses in the radial direction centering on the contact portion with each of the convex portions 9, but the solidification progress rate in the internal direction of the hot water 3 at a high temperature is the cooling rate of the hot water 3. Since the solidification portion 10 is slower than the speed of solidification in the direction along the surface facing the roll 1, the solidification portion 10 is flattened along the surface facing the cooling roll 1 of the hot water 3, centering on the contact points with the respective convex portions 9. Will grow into a hemispherical shape.

  Thereafter, the solidification of the hot water 3 proceeds with time, and when the solidified portion 10 of the hot water 3 grows along the surface of the hot water 3 facing the cooling roll 1, as shown in FIG. After the solidified portions 10 formed around the contact points with the convex portions 9 come into contact with each other adjacent to each other, they are joined. As a result, the surface portion of the hot water 3 facing the cooling roll 1 is formed around the contact points with the individual convex portions 9, and then solidified in a state where the lens-shaped solidified portions 10 joined to each other are formed. It will be.

  Further, as the solidification of the hot water 3 progresses, as shown in FIG. 8 (c), the surface side of the hot water 3 facing the cooling roll 1 contracts as the solidification occurs. Each of the lens-like solidification portions 10 formed around the center of the lens is in a state of being collected in a required number, and each lens-like solidification portion 10 located on the outer periphery thereof excluding a certain solidification portion 10 located at the center portion of the collection. The solidified part 10 is lifted from the surface of the cooling roll 1 by the contraction force when the hot water 3 is solidified. A gap is formed between the lens-shaped solidified portion 10 floating above the surface of the cooling roll 1 and the cooling roll 1, and in the portion floating above the surface of the cooling roll 1 due to the presence of an air layer in the gap 3 Therefore, the subsequent solidification of the hot water 3 proceeds centering on the portion in contact with the convex portion 9 on the surface of the cooling roll 1. A larger lenticular solidified product 11 is formed which includes the required number of lenticular solidified portions 10.

  Further, as the solidification of the hot water 3 progresses, as the solidification shrinkage further occurs, the formed lens-like solidified substances 11 are grouped so as to be integrated around the required number, and positioned at the center. The portion excluding the contact portion with the certain convex portion 9 is lifted from the surface of the cooling roll 1 and the heat removal of the hot water 3 is suppressed at the lifted portion. A large lens-shaped solidified substance 11 is formed on the surface portion facing the center of the contact portion with a certain convex portion 9 for each required region. Since the formation of the lens-like solidified material 11 proceeds simultaneously with the passage of time at a number of locations on the outer peripheral surface of the roll, the lens-like solidified portions 10 are joined to each other by a required number, for example, five. The formation of the solidified product 11 and the formation of a larger lenticular solidified product 11 by grouping the lenticular solidified products 11 together into a required number, for example, 5 pieces, proceed almost at the same time. Therefore, the size of the formed lenticular solid 11 increases stepwise as the solidification time of the hot water 3 elapses.

  Therefore, when the solidified product of the hot water 3 that has passed a certain solidification time is sent to the roll gap as the cooling rolls 1 rotate by contacting the roll surface, the surface portion of the hot water 3 that faces each cooling roll 1. The lens-shaped solidified material 11 having substantially the same size is formed at a required pitch. For this reason, the thin plate 4 formed by press-bonding the solidified products of the hot water 3 is formed on the surface portions of the respective cooling rolls 1 on both sides, as shown in FIG. The lenticular solidified product 11 is encapsulated in a tissue structure, and the surface thereof has shallow irregularities due to the formation of convex portions corresponding to the size of the lenticular solidified product 11 held inside. Is formed. In FIG. 9, for convenience, the irregularities formed on the surface of the thin plate 4 are highlighted.

  On the other hand, the unevenness in the longitudinal direction formed on the thin plate 4 produced when the chatter is generated is the pitch of the lenticular solidified material 11 formed when the hot water 3 is cooled at the surface portion of the cooling roll 1. It was found that it almost coincided with the diameter.

  From these, the unevenness formed on the thin plate 4 produced when the chatter is generated is the thin plate on which the lenticular solid product 11 formed when the hot water 3 solidifies on the surface portion of the cooling roll 1 is produced. 4, that is, when the hot water 3 is cooled and solidified at the surface portion of each of the cooling rolls 1, the lenticular solids 11 are aligned in the roll axis direction. It was thought that this was caused by the formation.

  Further, when the lens-like solidified material 11 is formed so as to be slightly aligned in the roll axis direction when it is formed on the surface portion of each cooling roll 1, the lens-shaped solidified material slightly aligned in the roll axis direction. When the object 11 passes between the two cooling rolls 1, the vibrations of the respective cooling rolls 1 slightly occur in the roll gap direction. It becomes a cause of causing alignment in the axial direction, and the lenticular solidified material 11 is further aligned in the roll axial direction, so that it is considered that chatter is generated.

  Therefore, as described in Patent Document 1, in the cooling roll 1 provided so that the same convex portions 5 are aligned in the roll axial direction, each convex portion 5 arranged along the roll axial direction has At the same time, since it can be the center of the lenticular solidified product, it is assumed that the lenticular solidified product 11 cannot be prevented from being formed aligned in the roll axis direction. .

  On the other hand, as described in the above-mentioned Patent Document 2, in the case where unevenness is formed on the outer peripheral surface of the roll by sandblasting, the shape of each convex part itself is random, and the arrangement is also random. Therefore, although chatter is relatively unlikely to occur, the above-mentioned hot water is generally used because substantially the same convex portions can be regarded as being arranged almost evenly on the entire outer surface of the roll. Therefore, it is not possible to reliably prevent the lenticular solid material 11 from being formed so as to be aligned in the roll axis direction during solidification of No. 3, and thus it is not possible to reliably prevent the generation of chatter.

  Therefore, if the lens-like solidified product 11 is not aligned in the roll axis direction of the cooling roll 1, the thin plate 4 to be manufactured has a thick portion and a thin portion corresponding to each lens-like solidified product 11. The inventors have found that chattering can be prevented even if a portion is generated, and have made the present invention.

  Therefore, the object of the present invention is to prevent the lenticular solid formed on the surface of the hot water facing the cooling roll from being aligned in the roll axis direction of the cooling roll when the raw material alloy hot water is solidified. Thus, the present invention is intended to provide a cooling roll for strip casters that can prevent the occurrence of chatter.

  In order to solve the above-mentioned problem, the present invention provides a strip caster cooling roll in which convex portions having a required shape are provided over the entire surface at a predetermined pitch on the outer peripheral surface of the roll. The solidification center forming convex portions are provided so that the extraction of hot water can be performed more efficiently than the other convex portions, and the solidification center forming convex portions are not aligned in the roll axis direction and the roll. It is configured to be provided at a required pitch over the entire outer peripheral surface.

  The solidification center forming convex portion is configured such that the groove formed around the solidification center forming convex portion is shallower than the groove formed around the other convex portion.

  Further, the solidification center forming convex portion is configured such that the area of the top portion of the solidification center forming convex portion is larger than the area of the top portion of the peripheral convex portion.

  Further, the solidification center forming convex portion is configured such that the height of the solidification center forming convex portion is higher than the height of the surrounding convex portions.

  Further, the solidification center forming convex portion is arranged on the outer peripheral surface of the roll so that the side direction and the diagonal direction of the minimum parallelogram formed by the solidification center forming convex portion are both shifted from the roll axis direction by a required angle. The configuration.

  Furthermore, the tangent of the angle formed by the right and left closest alignment directions of the convex portions provided on the outer peripheral surface of the roll at a required pitch and the roll axis direction is not less than 1/7 and smaller than 1/2. The configuration is as follows.

According to the cooling roll for strip casters of the present invention, the following excellent effects are exhibited.
(1) In a cooling roll for strip casters in which convex portions having a required shape are provided over the entire surface at a predetermined pitch on the outer peripheral surface of the roll, hot water is supplied more than other peripheral convex portions for each required number of the convex portions. Protrusions for forming solidification centers that enable efficient heat removal are provided, and the solidification center formation protrusions are not aligned with each other in the roll axis direction, and a required pitch is provided over the entire outer surface of the roll. Therefore, the hot water can be solidified more efficiently at the contact point with the solidification center forming convex part than at the contact part with the surrounding convex part. For this reason, the lenticular solid formed when the hot water solidifies can be formed around the contact portion between the solidification center forming convex portion and the hot water. At this time, since the solidification center forming convex portions are arranged so as not to be aligned in the roll axis direction of the cooling roll, the formed lenticular solid products are formed so as to be aligned in the roll axis direction. Therefore, the possibility of chattering can be prevented.
(2) The solidification center forming convex portion has a structure in which the groove formed around the solidification center forming convex portion is shallower than the groove formed around the other convex portion, thereby solidifying the solidification center forming convex portion. The air layer in the groove around the center forming convex part is made thinner than the air layer present in the groove around the other convex part, so that the action of suppressing the heat removal from the hot water can be reduced. The solidification center forming convex portion can efficiently solidify the hot water as compared with other convex portions.
(3) The solidification center forming convex portion has a configuration in which the area of the top portion of the solidification center forming convex portion is larger than the area of the top portion of the surrounding convex portions, or the solidification center forming convex portion By adopting a configuration in which the height of the portion is higher than the height of the surrounding convex portion, the solidification center forming convex portion can efficiently remove hot water as compared to other convex portions. Therefore, the hot water can be solidified efficiently.
(4) The solidification center forming convex portion is arranged on the outer peripheral surface of the roll so that both the side direction and the diagonal direction of the minimum parallelogram formed by the solidification center forming convex portion are deviated from the roll axis direction by a required angle. With this configuration, the solidification center forming convex portions can be easily provided on the outer peripheral surface of the cooling roll without being aligned in the roll axis direction.
(5) Also, the tangent of the angle formed by the right and left closest alignment directions of the convex portions provided on the outer peripheral surface of the roll at the required pitch and the roll axis direction is 1/7 or more and smaller than 1/2. By adopting such a configuration, when solidification is started in a state where hot water is dispersed from the contact portions with the respective convex portions and the respective solidification center forming convex portions, the direction in which the respective solidification start locations are aligned is determined. It can be shifted from the roll axis direction. For this reason, it becomes possible to suppress that the lenticular solidified product formed by joining the solidified portions of the hot water formed at the respective solidification start locations is formed so as to be aligned in the roll axis direction.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIGS. 1 (a), (b), (c) and FIG. 2 show an embodiment of a cooling roll for strip casters according to the present invention, which is used for a twin roll strip caster having the same configuration as shown in FIG. A large number of convex portions 12 having the same shape required to cause the cooling roll 1 to be solidified from a large number of locations on the surface of the cooling roll 1 on the outer peripheral surface of the cooling roll 1, The solidified center forming convex portion 13 is provided over the entire surface at a required pitch and is capable of solidifying the raw material alloy hot water 3 more efficiently than the convex portions 12. The cooling roll 1a for strip casters of the present invention is assumed to be provided on the entire outer peripheral surface of the roll at a given pitch so that the convex portions 13 are not aligned in the roll axial direction S.

Details will be described below.
As shown in FIGS. 1B and 1C, each of the convex portions 12 is, for example, a top (rectangle) 140 mm square and square (square), a height of 40 μm, and cooled at a pitch of 200 μm vertically and horizontally. It is disposed on the outer peripheral surface of the roll 1a. In other words, the grooves 12 having a depth of 40 μm and a width of 60 μm are formed on the outer peripheral surface of the cooling roll 1 a in a lattice shape at a pitch of 200 μm in length and width, thereby forming the convex portions 12.

  On the other hand, each solidification center forming convex portion 13 has a top portion flush with the convex portion 12, and the top shape of the top portion is a rectangular of 140 μm in length and width similar to the convex portion 12. The depth dimension of the groove 15 around the solidification center forming convex portion 13 is shallower than the depth dimension of the groove 14 formed around the other convex portion 12, for example, about 20% shallower. is there. As a result, when the raw material alloy hot water 3 comes into contact with the convex portions 12 formed on the outer peripheral surface of the cooling roll 1a and the tops of the solidified center forming convex portions 13, the solidification center forming convex portions 13 The thickness of the air layer existing in the surrounding grooves 15 is made smaller than the thickness of the air layer existing in the grooves 14 formed around the other protrusions 12 to reduce the heat removal suppression action by the air layers. Thus, the heat removal from the hot water 3 at the contact point with the solidification center forming convex part 13 can be performed more efficiently than the heat removal at the contact part with the other convex part 12. Thus, the hot water 3 can be efficiently solidified at the contact portion with the solidification center forming convex portion 12.

  Further, the solidification center forming convex portion 13 is grown in a step-like manner by the mechanism shown in FIGS. 8 (A), (B) and (C) when the raw material alloy hot water 3 is solidified. If it is arranged on the outer peripheral surface of the roll at substantially equal intervals with a required pitch which is almost the same as the diameter of the lenticular solid 11 of the hot water 3 assumed to be formed or less than the diameter of the lenticular solid 11 and as large as possible. At the same time, two pairs of opposite directions and two diagonal lines x, y of the minimum parallelogram (indicated by a one-dot chain line in FIG. 1A) formed by the solidification center forming convex portions 13 arranged at the required pitch. Are arranged so as to deviate from the roll axis direction S by a required angle.

  Specifically, the lens-like solidified product 11 finally formed as the hot water 3 is solidified is formed, for example, at each solidification start location of the hot water 3 as shown in FIG. In the case where it is assumed that the size of the portion 10 is such that 16 pieces are joined or slightly larger than that, the solidification center formation with respect to the fifteen convex portions 12 is performed as shown in FIG. One convex portion 13 is provided at a rate of one.

  Further, in the case where the convex portions 12 and the solidification center forming convex portions 13 are arranged in a pattern as shown in FIG. 1A, the direction in which the convex portions 12 are aligned closest to the left and right ( The angle θ formed between each convex portion 12 and the roll axis direction S is such that tan θ is 1/7 or more and smaller than 1/2. An angle range is set. As described above, the angle θ formed by the right and left closest alignment direction of each convex portion 12 and the roll axis direction S is set to an angle range in which tan θ is 1/7 or more and smaller than 1/2. When the angle θ formed by the right and left closest packing direction of the portion 12 and the roll axis direction S is an angle range in which tan θ takes a value smaller than 1/7, the left and right closest packing directions of the respective convex portions 12 are along. The solidification center forming convex portions 13 are arranged so as to be aligned substantially in parallel with the roll axis direction S, and the solidification center forming convex portions as shown by a one-dot chain line in FIG. Among the two diagonal lines x and y of the smallest parallelogram formed by 13, the direction of one diagonal line x that is arranged along the left-right closest alignment direction of the convex portions 12 is substantially in the roll axis direction S. It is because it becomes parallel and becomes unpreferable. On the other hand, when the angle θ formed by the right and left closest alignment direction of each convex portion 12 and the roll axis direction S is an angle at which tan θ is ½, the solidification center formation as shown by the one-dot chain line in FIG. This is because the direction of one set of opposite sides of the two sets of opposite sides of the minimum parallelogram formed by the convex portions 13 for use becomes parallel to the roll axis direction S, which is not preferable. In FIG. 1A, the left and right close-packed alignment directions of the convex portions 12 are shown as being shifted upward at the angle θ with respect to the roll axis direction S. The left and right close-packed alignment directions may be shifted downward with respect to the roll axis direction S at the angle θ. In FIGS. 1A and 1B, for convenience, the solidification center forming convex portion 13 is hatched (the same applies to FIGS. 3 and 5 described later).

  When the strip caster cooling roll 1a of the present invention is used as a cooling roll for a twin roll strip caster as shown in FIG. The inside of the groove | channel 14 which respectively touches the convex part 12 in the outer peripheral surface of each cooling roll 1a, and the top part of the convex part 13 for solidification center formation, and becomes a recessed part between the said convex parts 12 by surface tension, and solidification center Solidification is started without contacting the inside of the groove 15 serving as a recess between the forming projection 13 and the surrounding projection 12. For this reason, since the hot water 3 starts to solidify in a dispersed state from the contact portions with the tops of the respective convex portions 12 and the top portions of the respective solidification center forming convex portions 13, the raw material alloy hot water 3 The generation of surface distortion of the thin plate 4 manufactured by reducing the rapid heat removal can be suppressed.

  At this time, since each of the solidification center forming convex portions 13 has the surrounding groove 15 shallower than the groove 14 formed around the other convex portion 12, an air layer existing in the groove 15 is formed. The action of suppressing the heat removal of the hot water 3 by the water is weaker than the action of suppressing the heat removal of the hot water 3 by the air layer present in the grooves 14 around the other protrusions 12. Accordingly, the hot water 3 is solidified more efficiently at the contact points between the solidification center forming convex portions 13 and the hot water 3 than the contact portions between the other convex portions 12 and the hot water 3.

  For this reason, the solidification of the hot water 3 proceeds on the surface portion of each cooling roll 1a by the same mechanism as shown in FIGS. The lens-shaped solidified portion 10 formed and grown at each contact point between the portion 13 and the convex portion 12 and the hot water 3 is sequentially joined to grow in size in a step shape, and finally a large lens-shaped solidified portion. When the product 11 is formed, each lenticular solid product 11 is formed around the contact point between the solidification center forming convex portion 13 and the hot water 3.

  As described above, the solidification center forming convex portions 13 are arranged on the outer peripheral surface of the cooling roll 1a so as not to be aligned in the roll axial direction S. As shown in FIG. 2, the lens-like solidified product 11 formed at the center is sequentially arranged on the surface portion of each cooling roll 1a that is rotationally driven so as to correspond to the arrangement of the solidification center forming convex portions 13. Since it is formed, it is prevented that the cooling rolls 1a are formed so as to be aligned in the roll axial direction S. In FIG. 2, the convex portion 12 is not shown for convenience.

  Therefore, when the thin plate 4 is formed when the solidified product of the hot water 3 solidified on the surface portion of each cooling roll 1a passes through the roll gap between the cooling rolls 1a, the thin plate 4 is formed. Alignment of the solidified product 11 in the roll axial direction S is prevented. For this reason, even if shallow irregularities are formed on the surface of the thin plate 4 due to the individual lenticular solids 11, the shallow irregularities are not aligned in the roll axial direction S of each cooling roll 1a. Each cooling roll 1a does not vibrate with a required amplitude in the roll gap direction to develop chatter.

  Thus, according to the cooling roll for strip casters of the present invention, the lens-like solidified material 11 formed when the hot water 3 is cooled at the surface portion of the cooling roll 1a is removed from the outer periphery of each cooling roll 1a. By forming each of the solidified center forming convex portions 13 arranged on the surface so as not to be aligned in the roll axis direction S, the arrangement of the lens-shaped solidified product 11 can be positively adjusted. The arrangement may be such that the roll axis direction S is not aligned. Accordingly, it is possible to prevent the possibility of chattering when the thin plate 4 is manufactured between the cooling rolls 1a.

  Further, each solidification center forming convex portion 13 can be formed by making the groove 15 engraved around it shallower than the groove 14 engraved around the other convex portion 12, and As shown in FIG. 1A, the grooves 15 and 14 for forming the solidification center forming convex portions 13 and the convex portions 12 are both in a grid pattern on the outer peripheral surface of each cooling roll 1a. For example, when the grooves 14 are engraved so as to form the projections 12 by using an NC lathe or the like, at positions corresponding to the arrangement of the solidification center forming projections 13, for example. By reducing the depth of the groove to be engraved so as to correspond to the depth dimension of the groove 15, the cooling roll 1a of the present invention can be easily manufactured.

  Next, FIG. 3 shows another embodiment of the present invention. In the cooling roll 1a having the same configuration as the embodiment shown in FIGS. 1 (a), (b), (c) and FIG. Instead of forming the solidification center forming convex portion 13 by making the groove 15 around the convex portion 13 shallower than the groove 14 provided around the other convex portion 12, the solidification center forming convex portion 13 is formed. Is formed such that the area of the top part is larger than the area of the top part of the other convex part 12.

  That is, the solidification center forming convex portion 13 has, for example, a top portion of 160 μm square and is wider than the area of the top portion (140 μm square) of the other convex portion 12, thereby increasing the contact area with the hot water 3. Expanding the heat removal from the hot water 3 at the place where the respective solidification center forming convex portions 13 and the hot water 3 are in contact with each other compared to removing heat from the hot water 3 at the contact portion between the other convex portions 12 and the hot water 3. In this way, the hot water 3 can be solidified more efficiently than the other protrusions 12.

  Other configurations are the same as those shown in FIGS. 1A, 1B and 1C, and the same components are denoted by the same reference numerals.

  Even when the cooling roll 1a for strip casters of the present embodiment is used as a cooling roll of a twin roll type strip caster as shown in FIG. 6, when the hot water 3 is solidified at the surface portion of each cooling roll 1a, Since the lens-like solidified product 11 can be formed around the solidification center forming convex portions 13, the lens-like solidified product 11 can be prevented from being aligned in the roll axial direction S. For this reason, the effect similar to the said embodiment can be acquired.

  Next, FIG. 4 shows still another embodiment of the present invention. In the cooling roll 1a having the same configuration as the embodiment shown in FIGS. 1 (a), (b), (c) and FIG. Instead of forming the solidification center forming convex portion 13 by making the groove 15 around the convex portion 13 shallower than the groove 14 provided around the other convex portion 12, the solidification center forming convex portion 13 is formed. Is formed with a height higher than that of the other protrusions 12.

  That is, the solidification center forming convex portion 13 has a height dimension of, for example, 45 μm, and the top of each solidification center forming convex portion is more outward than the other convex portions 12 having a height dimension of 40 μm. Thus, the heat removal from the hot water 3 at the place where the respective solidification center forming convex portions 13 and the hot water 3 are in contact with each other, and the hot water 3 at the contact portion between the other convex portions 12 and the hot water 3 is thereby prevented. The hot water 3 can be solidified more efficiently than the other protrusions 12 by performing the heat efficiently compared to the heat removal from the other.

  Other configurations are the same as those shown in FIGS. 1A, 1B and 1C, and the same components are denoted by the same reference numerals.

  Even when the cooling roll 1a for strip casters of the present embodiment is used as a cooling roll of a twin roll type strip caster as shown in FIG. 6, when the hot water 3 is solidified at the surface portion of each cooling roll 1a, Since the lens-like solidified product 11 can be formed around the solidification center forming convex portions 13, the lens-like solidified product 11 can be prevented from being aligned in the roll axial direction S. Therefore, the same effects as those of the embodiment shown in FIGS. 1A, 1B, and 2 and FIG. 2 can be obtained.

  In addition, this invention is not limited only to the said embodiment, In addition to the side dam 2, as a twin roll type strip caster, the lower end is the outer periphery of each cooling roll 1a above each cooling roll 1a. A barrel weir that is brought into contact with the surface over the entire length in the axial direction is provided, so that hot water can be accumulated at a required height level above the roll gap of the cooling roll 1a by each barrel weir and the side weir 2. You may apply also to the cooling roll 1a of the twin roll type strip caster of the type formed by forming the hot water sump part. The solidification center forming convex portion 13 projects in the outer peripheral direction by making the surrounding groove 15 shallower, making the area of the top portion wider, or by increasing the height dimension compared to the other convex portions 12. Although it is shown as any of the above, it is assumed that the surrounding groove 15 is shallower than the other protrusions 12, the top area is wide, and the protrusion protrudes in the outer peripheral direction. Any two or three of the features may be combined. Although the existence ratio of the solidification center forming convex portion 13 to the other convex portion 12 has been described as being 1:15, the size of the lenticular solidified material 11 formed when the hot water 3 is solidified is large or small. And the other convex part 12 of the solidification center formation convex part 13 according to the relationship between the size of the lenticular solidified product 11 and the vertical and horizontal arrangement pitches of the solidification center formation convex parts 13 and the convex parts 12. You may make it increase / decrease freely the abundance ratio with respect to. The solidification center forming convex portions 13 are aligned with the vertical and horizontal arrangements of the convex portions 12 and the right and left close-packed alignment directions of the convex portions 12 are shifted by a required angle from the roll axis direction S, thereby Although it is preferable to arrange the outer peripheral surface so as not to align with the roll axis direction S, more specifically, for example, as shown in FIG. As shown, each side and diagonal of the minimum parallelogram formed by each solidification center forming convex portion 13 (shown by a one-dot chain line in the figure) are shifted by a required angle so that none of them is parallel to the roll axis direction S. If so, the arrangement of the protrusions 12 may be freely set, for example, the protrusions 12 may be arranged so as to be aligned in the roll axis direction S and the circumferential direction. Although the solidification center forming convex portion 13 and the convex portion 12 are both shown as rectangular, the solidification center forming convex portion 13 can efficiently remove the hot water 3 more than the other convex portions 12. Of course, the shape may be arbitrarily set, and various changes can be made without departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a cooling roll for strip casters according to the present invention, in which (A) is a schematic side view, (B) is an enlarged view of a surface portion, and (C) is an AA of (B). FIG. It is a schematic diagram which shows arrangement | positioning of the lenticular solid material formed when hot water solidifies in the surface part of the cooling roll of FIG. It is a schematic side view which shows the other form of implementation of this invention. It is a figure corresponding to FIG. 1 (b) which shows other form of implementation of this invention. It is a schematic side view which shows other form of implementation of this invention. It is a cutting side view showing an outline of an example of a twin roll type strip caster. (A), (b), (c), (d), (e), and (f) are all schematic views showing surface portions in other types of cooling rolls for twin roll strip casters that have been conventionally proposed. This shows the process when the hot water of the raw material alloy is solidified at the surface part of the cooling roll with the convex part on the outer peripheral surface of the roll. (A) is the state where the solidification of the hot water is started from the contact point with the convex part (B) shows a state in which the lens-shaped solidified portions formed at the contact points with the convex portion are joined together, and (c) shows a state in which a large lens-shaped solidified product is formed around the certain convex portion. It is a schematic sectional drawing shown respectively. It is sectional drawing which shows the structure | tissue structure of the thin plate manufactured when the hot water solidified by the surface part of a pair of cooling roll is crimped | bonded by a roll gap.

Explanation of symbols

S Roll axis direction x Diagonal line y Diagonal line 1a Cooling roll 12 Convex part 13 Convex part for forming solidification center 14 Groove 15 Groove

Claims (6)

  In the cooling roll for strip casters in which convex portions of a required shape are provided on the outer peripheral surface of the roll over the entire surface at a predetermined pitch, the hot water is removed from the surrounding convex portions for each required number of the convex portions. Protrusions for forming solidification centers that can be efficiently performed are provided, and the solidification center formation protrusions are not aligned with each other in the roll axis direction and are provided at a required pitch over the entire surface of the roll outer peripheral surface. A cooling roll for strip casters, characterized in that it is configured as described above.   The cooling roll for strip casters according to claim 1, wherein the solidified center forming convex portion is formed such that a groove formed around the solidified center forming convex portion is shallower than a groove formed around the other convex portion. .   The cooling roll for strip casters according to claim 1, wherein the solidification center forming convex portion has an area of a top portion of the solidification center forming convex portion larger than an area of a top portion of a peripheral convex portion.   The cooling roll for a strip caster according to claim 1, wherein the solidification center forming convex portion has a height of the solidification center forming convex portion higher than that of the surrounding convex portion.   2. The solidification center forming convex portion is disposed on the outer peripheral surface of the roll so that both the side direction and the diagonal direction of the minimum parallelogram formed by the solidification center forming convex portion are deviated from the roll axis direction by a required angle. The cooling roll for strip casters according to 2, 3 or 4.   The tangent of the angle formed by the right and left closest alignment directions of the convex portions provided on the outer peripheral surface of the roll at a required pitch and the roll axis direction is 1/7 or more and less than 1/2. The cooling roll for strip casters according to 1, 2, 3 or 4.

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