JP2007203337A - Twin-roll casting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a twin-roll casting machine in which the unevenness of thickness distribution in the sheet width direction of strip can be restrained. <P>SOLUTION: The twin-roll casting machine is provided with cooling rolls 1a, 1b, side weirs 2a, 2b and nozzle pieces 11a,11b feeding molten metal toward the outer peripheral surfaces of the cooling rolls 1a, 1b, and the molten metal feeding ranges T, U through the one nozzle piece 11a are set as narrow to the axial direction of the one cooling roll 1a and as wide to the axial direction of the other cooling roll 1b, and the molten metal feeding ranges V, W through the other nozzle piece 11b are set as wide to the axial direction of the one cooling roll 1a and as narrow to the axial direction of the other cooling roll 1b. In this way, the low temperature range X between the molten metal feeding ranges T and V at the one cooling roll 1a side and the low temperature range X between the molten metal feeding ranges U and W at the other cooling roll 1b side are made not to face each other in the diameter direction of the cooling rolls 1a, 1b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a twin roll casting machine.

  As a method for directly producing a strip from a molten metal, there is a twin-roll continuous casting method in which the molten metal is supplied between a pair of rotating rolls and the solidified metal is fed into a thin strip shape.

  5 to 7 show an example of a conventional twin roll casting machine, a pair of cooling rolls 1a and 1b arranged side by side, and a pair of side weirs 2a and 2b attached to the cooling rolls 1a and 1b. It has.

  The cooling rolls 1a and 1b are configured such that cooling water flows therethrough and the roll gap G can be adjusted in accordance with the thickness of the strip 3 to be produced.

  The rotation direction and speed of the cooling rolls 1a and 1b are set so that the outer peripheral surfaces of the cooling rolls 1a and 1b move from the upper side toward the roll gap G at a constant speed.

  One side weir 2a is in surface contact with one end of each cooling roll 1a, 1b, and the other side weir 2b is in surface contact with the other end of each cooling roll 1a, 1b, and the cooling rolls 1a, 1b and side weir 2a , 2b, the nozzle pieces 4a, 4b for supplying molten metal are arranged so as to be located immediately above the roll gap G (see, for example, Patent Document 1).

  One nozzle piece 4a is supported so as to maintain a constant gap with respect to one side weir 2a, and the other nozzle piece 4b is supported so as to maintain a constant interval with respect to the other side weir 2b. Yes.

  The nozzle pieces 4a and 4b have an elongated nozzle trough 6 for receiving the molten metal 5 at the top thereof, and penetrate from the nozzle trough 6 toward the outer peripheral surface of the cooling rolls 1a and 1b in the portion near the lower end of the longitudinal side wall. A plurality of openings 7 are formed so as to be aligned along the axis of the cooling rolls 1 a and 1 b, and when the molten metal 5 is poured into each nozzle trough 6, the molten metal contacting the outer peripheral surfaces of the cooling rolls 1 a and 1 b above the roll gap G. A reservoir 8 is formed.

  The opening position of the opening 7 in the nozzle piece 4a is such that the molten metal feeding range P toward one cooling roll 1a and the molten metal feeding range Q toward the other cooling roll 1b are the axes of the cooling rolls 1a and 1b. It is set to align in the direction.

  In addition, the drilling position of the opening 7 in the nozzle piece 4b also includes the molten metal feeding range R toward the one cooling roll 1a and the molten metal feeding range S toward the other cooling roll 1b. It is set to be aligned in the axial direction.

  In the twin roll casting machine described above, when the above-described molten metal pool 8 is formed and the cooling rolls 1a and 1b are rotated while removing heat from the cooling rolls 1a and 1b by circulating cooling water, the molten metal 5 becomes the cooling roll 1a. , 1b is solidified on the outer peripheral surface to form a solidified shell 9, and the strip 3 is fed downward from the roll gap G.

At this time, loads in directions close to each other are applied to the neck portions of the cooling rolls 1a and 1b so that the produced strip 3 has a target plate thickness.
JP 2000-202590 A

  However, as shown in FIG. 6A, the molten metal feed ranges P and Q of one nozzle piece 4a are aligned in the axial direction of the cooling rolls 1a and 1b, and the molten metal feed ranges R and S of the other nozzle piece 4b. Are also aligned in the axial direction of the cooling rolls 1a and 1b, so that the low temperature region X is between the molten metal supply range PR on the cooling roll 1a side of the molten metal reservoir 8 and the cooling roll 1b side of the molten metal reservoir 8 is. Appears between the molten metal feeding range Q-S so that the low temperature region X is opposed to the cooling rolls 1a, 1b in the radial direction.

  As shown in FIG. 6 (b), these low temperature regions promote the generation (increase in thickness) of the solidified shell 9 at the axially intermediate portion of the outer peripheral surfaces of the cooling rolls 1a and 1b, and are sent from the cooling rolls 1a and 1b. As shown in FIG. 6 (c), the strip 3 to be formed has a thickened solidified shell 9 only at the central portion in the plate width direction, but other than that, an unsolidified region remains at the edge portion (edge portion) in the plate width direction. become.

  For this reason, as shown in FIG. 6D, the strip 3 after the reduction by solidification has a cross-sectional shape in which the thickness is locally increased on both the front and back surfaces at the central portion in the width direction, and the thickness distribution in the plate width direction is reduced. There is a case in which the bias becomes excessive, and the winding of the strip 3 may be difficult.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a twin-roll casting machine capable of suppressing the deviation in the thickness distribution of the strip in the plate width direction.

  In order to achieve the above object, the present invention provides a pair of cooling rolls, a pair of side weirs, and a base end that maintains a constant gap with respect to one side weir and is directed toward the outer peripheral surface of each cooling roll. One nozzle piece, and the other nozzle piece that supplies a molten metal toward the outer peripheral surface of each cooling roll while maintaining a constant interval with respect to the other side weir. The molten metal feeding range by the nozzle piece is set narrow for the axial direction of one cooling roll and wide for the axial direction of the other cooling roll, and the molten metal feeding range by the other nozzle piece is It is set to be wide with respect to the axial direction of the other cooling roll and narrow with respect to the axial direction of the other cooling roll.

  That is, the expansion of the molten metal feeding range with respect to the axial direction of the one cooling roll and the expansion of the molten metal feeding range with respect to the axial direction of the other cooling roll are made different for each nozzle piece, and between the molten metal feeding range on the one cooling roll side. The low temperature region between the low temperature region and the molten metal feeding range on the other cooling roll side should not be opposed in the cooling roll radial direction.

  Furthermore, the molten metal feed ranges that are set widely with respect to the cooling roll axis direction of each nozzle piece are set so as to overlap each other, and the temperature difference in the roll axis direction of the molten metal between the cooling rolls is reduced.

  According to the twin roll casting machine of the present invention, the following excellent effects can be obtained.

  (1) For each nozzle piece, the expansion of the molten metal feeding range with respect to the axial direction of one cooling roll is different from the expansion of the molten metal feeding range with respect to the axial direction of the other cooling roll. The low-temperature region on the cooling roll side and the low-temperature region on the other cooling roll side do not face each other in the radial direction of the cooling roll, so that it is possible to suppress the uneven thickness distribution in the strip width direction of the strip.

  (2) If the molten metal feeding ranges that are set widely with respect to the cooling roll axis direction of each nozzle piece are set so as to overlap each other, the temperature difference in the roll axis direction of the molten metal between the cooling rolls is reduced, and the strip The plate width direction thickness distribution approaches a uniform state.

  (3) Since unevenness of the thickness distribution in the strip width direction of the strip is suppressed and approaches a uniform state, winding of the strip does not become difficult.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show an example of a twin roll casting machine according to the present invention, which includes cooling rolls 1a and 1b, side weirs 2a and 2b, and nozzle pieces 11a and 11b. In addition, FIGS. The part which attached | subjected the same code | symbol represents the same thing.

  One nozzle piece 11a is positioned right above the roll gap G and supported so as to maintain a constant gap with respect to one side weir 2a, and the other nozzle piece 11b is positioned right above the roll gap G. In addition, it is supported so as to maintain a constant interval with respect to the other side weir 2b.

  The nozzle pieces 11a and 11b have an elongated nozzle trough 6 for receiving the molten metal 5 at the top thereof, and an opening penetrating from the nozzle trough 6 toward the outer peripheral surface of the cooling rolls 1a and 1b at the lower end portion of the longitudinal side wall. 7 is formed so as to be aligned along the axis of the cooling rolls 1a and 1b, and when the molten metal 5 is poured into each nozzle trough 6, the molten metal pools contacting the outer peripheral surfaces of the cooling rolls 1a and 1b above the roll gap G. 8 is formed.

  Opposing ends of the nozzle pieces 11a and 11b are formed obliquely with respect to the end faces of the cooling rolls 1a and 1b.

  As for the drilling position of the opening 7 in the nozzle piece 11a, the molten metal feeding range T toward the cooling roll 1a is narrow in the axial direction of the cooling rolls 1a and 1b, and the molten metal feeding range U toward the cooling roll 1b is the cooling roll. It is set to be wide in the 1a and 1b axial directions.

  The opening position of the opening 7 in the nozzle piece 11b is such that the molten metal feeding range V toward the cooling roll 1a is wide in the axial direction of the cooling rolls 1a and 1b, and the molten metal feeding range W toward the cooling roll 1b is the cooling roll. It is set so as to become narrower in the 1a and 1b axial directions.

  In the twin roll casting machine described above, when the above-described molten metal pool 8 is formed and the cooling rolls 1a and 1b are rotated while removing heat from the cooling rolls 1a and 1b by circulating cooling water, the molten metal 5 becomes the cooling roll 1a. , 1b is solidified on the outer peripheral surface to form a solidified shell 9, and the strip 3 is fed downward from the roll gap G.

  At this time, as shown in FIG. 1 (a), the melt feed ranges T and U of the one nozzle piece 11a are different in the axial direction of the cooling rolls 1a and 1b, and the melt feed of the other nozzle piece 11b is further increased. The cooling rolls 1a and 1b in the feed ranges V and W are also spread in the axial direction, so that the cooling of the low temperature region X and the molten metal pool 8 appearing between the molten metal feed range TV on the cooling roll 1a side of the molten metal pool 8 is performed. The low temperature region X appearing between the molten metal feeding range U-W on the roll 1b side is not relative to the cooling rolls 1a and 1b in the radial direction.

  As shown in FIG. 1 (b), these low-temperature regions are generated by the solidified shell 9 at the portion near the side weir 2a on the outer peripheral surface of the cooling roll 1a and at the portion near the side weir 2b on the outer peripheral surface of the cooling roll 1b. As shown in FIG. 1C, the strip 3 that promotes (increase in thickness) and is fed from the cooling rolls 1a and 1b has the solidified shell 9 slightly at two locations away from the center in the plate width direction. Become thicker.

  For this reason, the strip 3 after the unsolidified region such as the edge portion (edge portion) in the plate width is solidified and the reduction is completed is a portion close to one edge portion as shown in FIG. The thickness increases on the back surface, and the cross-sectional shape increases in thickness on the surface near the other edge portion. When compared with the conventional example of FIG. 1, the uneven thickness distribution in the plate width direction of the strip 3 is dispersed. It looks like it, so that it is not difficult to wind up the strip 3.

  FIG. 3 shows an example of a specific shape of the opposed ends of the nozzle pieces 11a and 11b. In the figure, the portions denoted by the same reference numerals as those in FIGS. 1 and 2 represent the same thing.

  In this example, a wide molten metal feeding range U from one nozzle piece 11a toward the cooling roll 1b (see FIG. 1) and a wide molten metal feeding range V from the other nozzle piece 11b toward the cooling roll 1a (see FIG. 1). Are set such that the inclination angle of the opposed ends of the nozzle pieces 11a and 11b, the position where the opening 7 (see FIG. 2) near the opposed ends of the nozzle pieces 11a and 11b is formed, and the like.

  Thereby, the temperature difference between the molten metal feeding ranges T, U, V, W and the low temperature region X is reduced, and there is no significant difference in the generation of the solidified shell 9 (see FIG. 1), and the strip 3 (see FIG. 2). The thickness distribution in the plate width direction approaches a more uniform state.

  Further, it is possible to eliminate the low temperature region X by increasing the height dimension of the opening 7 (see FIG. 2) in the vicinity of the opposite ends of the nozzle pieces 11a and 11b and increasing the amount of molten metal delivered at the portion.

  FIG. 4 shows another example of the specific shape of the opposed ends of the nozzle pieces 11a and 11b. In the figure, the parts denoted by the same reference numerals as those in FIGS. 1 to 3 represent the same thing.

  In this example, the opposed ends of the nozzle pieces 11a and 11b are not formed as a single plane, but are bent when viewed from above.

  In addition, the twin roll casting machine of this invention is not limited only to embodiment mentioned above, Of course, it can add a change in the range which does not deviate from the summary of this invention.

  The twin roll casting machine of the present invention can be applied to the production of various metal strips including steel.

It is a conceptual diagram which shows the relationship between the nozzle piece, the molten metal feed range, the low temperature area | region of a molten metal pool, and strip cross-sectional shape in an example of the twin roll casting machine of this invention. It is a conceptual diagram which shows the state which looked at the twin roll casting machine of FIG. 1 in perspective. It is a partial horizontal sectional view which shows an example of the specific shape of the opposing end of a nozzle piece. It is a partial horizontal sectional view which shows the other example of the specific shape of the opposing end of a nozzle piece. It is a conceptual diagram which shows the state which looked at an example of the conventional twin roll casting machine in the cooling roll radial direction. It is a conceptual diagram which shows the relationship between the nozzle piece, the molten metal feeding range, the low temperature area | region of a molten metal pool, and strip cross-sectional shape in the twin roll casting machine of FIG. It is a conceptual diagram which shows the state which looked at the twin roll casting machine of FIG. 5 in perspective.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Cooling roll 1b Cooling roll 2a Side weir 2a Side weir 5 Molten metal 11a Nozzle piece 11b Nozzle piece T Molten metal feeding range U Molten metal feeding range V Molten metal feeding range W Molten metal feeding range

Claims (4)

  A pair of cooling rolls, a pair of side weirs, a nozzle piece whose base end portion maintains a constant gap with respect to one side weir and feeds molten metal toward the outer peripheral surface of each cooling roll; And the other nozzle piece that feeds the molten metal toward the outer peripheral surface of each cooling roll with the end portion maintained at a constant interval with respect to the other side weir, the molten metal feeding range by one nozzle piece, It is narrow for the axial direction of the other cooling roll and wide for the axial direction of the other cooling roll, and the molten metal feeding range by the other nozzle piece is wide for the axial direction of the one cooling roll. And the twin roll casting machine characterized by setting narrowly with respect to the axial direction of the other cooling roll.   The twin roll casting machine according to claim 1, wherein the molten metal feeding ranges that are set widely with respect to the cooling roll axis direction of each nozzle piece are set so as to overlap each other.   The twin roll casting machine according to claim 1 or 2, wherein opposing ends of both nozzle pieces are formed obliquely with respect to the end face of the cooling roll.   The twin roll casting machine according to claim 1 or 2, wherein opposing ends of both nozzle pieces have a bent shape as viewed from above.

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