JP2006312173A - Twin roll casting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a twin roll casting machine which can suppress the decrease of the thickness of a strip at its edge portions in the direction of its width. <P>SOLUTION: The twin roll casting machine comprises cooling rolls 1, a side weir 2, and a molten metal supply nozzle 4, wherein the flow S of the molten metal toward a roll gap G is suppressed by a baffle 11 provided such that the baffle 11 is connected to the lower portion of the end face of the molten metal supply nozzle 4 and projects toward the side weir 2 in a molten metal reservoir 8. As a result, the hot molten metal just after being poured does not directly arrive to the roll gap G by moving along the side weir 2, but the low temperature molten metal cooled with a lapse of time after being poured is brought into the roll gap G by being accompanied by the rotation of the cooling rolls 1. Therefore, the delay of the generation of a solidified shell in the neighborhood of the edge portion of the outer circumference of the cooling rolls 1 does not occur, and the thickness of the strip 3 delivered from the roll gap G does not decrease at the edge portion in the direction of the width, and the strip 3 having a uniform thickness over the whole width can be produced. <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.

  FIG. 5 shows an example of a twin roll casting machine, which includes a pair of cooling rolls 1 arranged horizontally and a pair of side weirs 2 attached to the cooling roll 1.

  The cooling roll 1 is configured such that cooling water flows through the roll 1 and the roll gap G can be adjusted in accordance with the thickness of the strip 3 to be produced.

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

  One side weir 2 is in surface contact with one end of each cooling roll 1, and the other side weir 2 is in surface contact with the other end of each cooling roll 1, and is surrounded by the cooling roll 1 and the side weir 2. The molten metal supply nozzle 4 made of a refractory material is disposed so as to be positioned immediately above the roll gap G.

  The molten metal supply nozzle 4 has an elongated nozzle trough 6 for receiving the molten metal 5 at the top, and an opening 7 penetrating from the nozzle trough 6 toward the outer peripheral surface of the cooling roll 1 is cooled in a portion near the lower end of the longitudinal side wall. A plurality of holes are formed so as to be aligned along the axis of the roll 1, and when the molten metal 5 is poured into the nozzle trough 6, a molten metal pool 8 that is in contact with the outer peripheral surface of the cooling roll 1 is formed above the roll gap G.

  That is, when the cooling roll 1 is rotated while the cooling roll 1 is removed by circulation of the cooling water and the cooling roll 1 is rotated, the molten metal 5 is solidified on the outer peripheral surface of the cooling roll 1 and downward from the roll gap G. The strip 3 is sent out.

  In addition, the solidified shell may be abnormally generated at a so-called triple point where the cooling roll 1, the side weir 2, and the molten metal reservoir 8 are in contact.

  When the solidified shell at the triple point is pulled by the solidified shell on the outer peripheral surface of the cooling roll 1 and peeled off, not only does it cause a shape defect in which the strip 3 is locally thickened by being caught in the roll gap G. The part expands the roll gap G, and the side weir 2 is damaged when the strip 3 breaks or the solidified shell falls off due to reduction in cooling efficiency and recuperation from the molten metal 5.

Therefore, a twin roll casting machine has been proposed in which the molten metal 5 is directed toward the side weir 2 and actively supplied in the tangential direction of the cooling roll 1 to suppress the formation of unnecessary solidified shells (for example, Patent Document 1). reference).
JP-A 62-45456

  However, in the twin roll casting machine of Patent Document 1, the high-temperature molten metal 5 just poured has reached the roll gap G in a very short time along the side weir 2, and the cooling roll 1 outer peripheral surface edge portion. The formation of solidified shells in the vicinity is delayed.

  For this reason, the board thickness direction edge part (edge part) of the strip 3 sent out from the roll gap | interval G tends to reduce, and it was difficult to make uniform board thickness over the strip 3 full width.

  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 a reduction in the thickness of the strip width direction edge portion of the strip.

  In order to achieve the above object, the present invention provides a baffle that suppresses the flow of the molten metal toward the roll gap along the side weir in the twin roll casting machine including the cooling roll, the side weir, and the molten metal supply nozzle. .

  As a specific baffle, a configuration in which the inside of the molten metal pool protrudes from the lower portion of the nozzle end surface toward the side weir, or a configuration in which the inside of the molten metal pool protrudes from the side weir toward the lower portion of the nozzle end surface is adopted.

  Separately, the nozzle end is extended to the side weir, and a baffle that protrudes from the middle lower edge in the nozzle longitudinal direction toward the side weir and forms a gap with respect to the nozzle end lower edge, or is provided from the side weir to the nozzle. A baffle is provided that protrudes toward the longitudinal middle lower edge and forms a gap with respect to the lower edge of the nozzle end.

  In the present invention, in order to prevent the hot molten metal just poured from reaching the roll gap immediately along the side weir, the flow of the molten metal going to the roll gap is suppressed by the baffle, and the vicinity of the cooling roll outer peripheral surface edge. Eliminates the delay in the formation of solidified shells.

  Further, the nozzle end is extended to the side weir so that the high temperature molten metal is not poured directly onto the roll gap near the side weir and the area where the molten metal contacts the side weir is reduced.

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

  (1) The flow of the molten metal going to the roll gap by the baffle is suppressed, and the delay in the formation of the solidified shell near the edge of the outer peripheral surface of the cooling roll is eliminated, so the edge in the plate width direction of the strip fed from the roll gap Thus, a strip having a uniform thickness over the entire width can be obtained.

  (2) By extending the nozzle end to the side weir, the molten metal is prevented from being poured directly onto the roll gap close to the side weir, and the delay in solidification shell formation near the outer peripheral edge of the cooling roll is eliminated. Therefore, the thickness of the strip in the width direction of the strip fed from the roll gap does not decrease, and a strip having a uniform thickness over the entire width can be obtained.

  (3) By extending the nozzle end to the side weir, the contact area of the molten metal with respect to the side weir is narrowed, so that generation of unnecessary solidified shells can be suppressed.

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

  1 and 2 show a first example of an embodiment of a twin roll casting machine according to the present invention. In the figure, the same reference numerals as those in FIG. 5 denote the same parts.

  In the twin roll casting machine including the cooling roll 1, the side weir 2, and the molten metal supply nozzle 4, a baffle 11 is provided that continues to the lower part of the end surface of the molten metal supply nozzle 4 and protrudes through the molten metal reservoir 8 toward the side weir 2. Yes.

  The tip of the baffle 11 is in contact with the side weir 2, or the gap with respect to the side weir 2 is reduced as much as possible, and the gap of the baffle 11 with respect to the outer peripheral surface of the cooling roll 1 is also as narrow as possible. To do.

  In this twin-roll caster, the flow S of the molten metal near the side weir 2 is suppressed from going directly to the roll gap G by the baffle 11 and is guided in a direction with less resistance, that is, toward the middle in the longitudinal direction of the cooling roll 1. Therefore, the hot molten metal that has just been poured does not reach the roll gap G along the side weir 2, and the molten metal whose temperature has decreased after the pouring is accompanied by the rotation of the cooling roll 1. It will enter the roll gap G.

  Thereby, the delay of solidification shell generation near the edge of the outer peripheral surface of the cooling roll 1 near the side weir 2 is eliminated, and the plate thickness in the plate width direction edge of the strip 3 fed from the roll gap G does not decrease, The strip 3 having a uniform thickness over the entire width can be obtained.

  The baffle 11 may be connected to the side weir 2 and protrude through the molten metal reservoir 8 toward the lower part of the end surface of the molten metal supply nozzle 4, or as shown by a two-dot chain line in FIG. If a groove is formed on the upper surface and formed into a bowl shape, the molten metal flow S entering the groove can be expected to turn upward.

  3 and 4 show a second example of the embodiment of the twin roll casting machine of the present invention. In the figure, the same reference numerals as those in FIG. 5 denote the same parts.

  In a twin roll casting machine provided with a cooling roll 1, a side weir 2, and a molten metal supply nozzle 4, the end of the molten metal supply nozzle 4 is extended to the side weir 2, and the molten metal supply nozzle 4 extends from the lower middle intermediate edge to the side weir 2. A bowl-shaped baffle 13 that protrudes toward and forms a gap 12 with respect to the lower edge of the end of the molten metal supply nozzle 4 is provided.

  The tip of the baffle 13 is in contact with the side weir 2, or the gap with respect to the side weir 2 is reduced as much as possible, and the gap of the baffle 11 with respect to the outer peripheral surface of the cooling roll 1 is also as narrow as possible. To do.

  In this twin roll casting machine, since the end of the molten metal supply nozzle 4 is extended to the side weir 2, the molten metal is not directly poured directly above the roll gap G near the side weir 2, Since the contact area of the molten metal is narrowed, generation of unnecessary solidified shells can be suppressed.

  Furthermore, the flow S of the molten metal that is about to go out from the gap 12 adjacent to the side weir 2 is restrained from going directly to the roll gap G by the baffle 13 and has a low resistance, that is, in the middle of the longitudinal direction of the cooling roll 1. Since it is guided to the side, the molten metal whose temperature has been lowered over time after pouring enters the roll gap G as the cooling roll 1 rotates.

  A part of the molten metal flow S entering the groove on the upper surface of the baffle 13 is turned upward.

  Thereby, the delay of solidification shell generation near the edge of the outer peripheral surface of the cooling roll 1 near the side weir 2 is eliminated, and the plate thickness in the plate width direction edge of the strip 3 fed from the roll gap G does not decrease, The strip 3 having a uniform thickness over the entire width can be obtained.

  The baffle 13 may be configured to be continuous with the side weir 2 and protrude through the molten metal reservoir 8 toward the lower portion of the end surface of the molten metal supply nozzle 4, and a groove may not necessarily be formed on the upper surface of the baffle 13.

  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 fragmentary perspective view which shows the 1st example of embodiment 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 the cooling roll radial direction. It is a fragmentary perspective view which shows the 2nd example of embodiment 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. 3 in the cooling roll radial direction. It is a conceptual diagram which shows the state which looked at an example of the twin roll casting machine in the cooling roll axial direction.

Explanation of symbols

1 Cooling Roll 2 Side Weir 4 Molten Supply Nozzle 8 Molten Pool 11 Baffle 12 Gap 13 Baffle G Roll Gap S Flow

Claims (8)

  The twin roll casting machine provided with the baffle which suppresses the flow of the molten metal which goes to a roll gap | interval along a side dam in the twin roll casting machine provided with the cooling roll, the side dam, and the molten metal supply nozzle.   A twin-roll casting machine comprising a cooling roll, a side weir, and a molten metal supply nozzle, wherein a baffle is provided that protrudes from the lower part of the nozzle end surface toward the side weir through the molten metal pool.   A twin-roll casting machine comprising a cooling roll, a side dam, and a molten metal supply nozzle, wherein a baffle is provided that protrudes from the side dam toward the lower part of the nozzle end face through the molten metal pool.   In a twin roll casting machine equipped with a cooling roll, a side weir, and a molten metal supply nozzle, the nozzle end extends to the side weir, protrudes from the middle lower edge in the nozzle longitudinal direction toward the side weir, and against the nozzle end lower edge A twin roll casting machine characterized by providing a baffle that forms a gap.   In a twin roll casting machine equipped with a cooling roll, a side weir, and a molten metal supply nozzle, the nozzle end extends to the side weir, protrudes from the side weir toward the middle longitudinal edge in the nozzle longitudinal direction, and against the nozzle end lower edge A twin roll casting machine characterized by providing a baffle that forms a gap.   The twin roll casting machine according to claim 1, wherein the baffle is brought into contact with the side weir.   The twin roll casting machine according to any one of claims 1, 3 and 5, wherein the baffle is brought into contact with the nozzle.   The twin roll casting machine according to any one of claims 1 to 7, wherein the baffle is formed in a bowl shape.

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