JPH02220742A - Metal strip continuous casting machine - Google Patents

Abstract

PURPOSE:To stably produce a continuously cast steel strip having the excellent accuracy of the strip thickness distribution by making the upward widening mold of pouring basin part between endless belts and making the shafts of one pair of lower rolls for shifting belts at the outlet of the cast steel strip capable of crossing at the time of continuously casting the steel strip with the endless twin belt type continuous casting machine. CONSTITUTION:The endless-like belt 1, 1' are endlessly shifted in the arrow mark directions 5, 5' with upper rolls 2, 2', lower rolls 3, 3' and guiding rolls 8, 8', and molten steel is poured into the pouring basin part 9 formed with the upper and lower rolls and both side weirs 7, 7' arranged at both ends of the rolls, and the belts 1, 1' are cooled from back faces with cooling devices 4, 4', and the molten steel is continuously drawn as the cast strip 10. In this case, by mutually crossing the shafts of the lower rolls 3, 3' supporting both belts 1, 1' for forming drawing-out hole of the cast strip 10 at 2theta angle, the strip crown of the cast strip 10 is controlled, and the thickness distribution of the strip 10 is controlled to obtain the cast steel strip 10 having uniform thickness. Further, since the pouring basin part 9 has a upward widening shape, the belts are not damaged by the poured molten steel.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is directed to the continuous production of metal ribbons directly from molten metal.
Concerning continuous metal ribbon casting machine.

[Prior Art] It is preferable that a metal ribbon can be directly produced from molten metal because the rolling process can be greatly simplified. Figure 5 is JP-A-6L.
This is an example of a twin-drum metal ribbon continuous casting machine described in the -27675J+ publication. Molten metal 11 is poured into a sump formed by two rotating drums 18-1 and 18-2 that rotate in the direction of the arrow. The molten metal in contact with the rotating drum is cooled between points m and n to form a solidified shell,
The solidified shells generated on the rotating drums 18-1 and 18-2 are combined at point n and taken out as a metal ribbon IO. In order to increase productivity (tons/hour) with this method, the rotating tram must rotate faster,
Since the distance between the m point and the n point is short, if the spindle is rotated too quickly, the thickness of the solidified shell will be insufficient, making it impossible to produce a thin metal plate with a predetermined thickness. Furthermore, if the diameter of the rotating drum is increased, the equipment becomes extremely large-scale.

FIG. 6 shows an example of a twin-belt continuous metal ribbon casting machine described in Japanese Patent Application Laid-open No. 59-47047. The molten metal 11 is
Pulley 19-1.19-2.19- rotating in the direction of the arrow
The water is injected into a pool formed by the endless belt 1, which runs in a stretched manner, and the endless belt 1', which runs in a similar manner. Since the back surfaces of the endless healds 1 and 1' are cooled by cooling devices 21 and 21', the molten metal in contact with the endless belt forms a solidified shell, and when solidification is approximately completed, it is taken out as a metal plate IO. In order to manufacture thin metal plates using this method, the distance t between the endless belts 1 and 1' must be narrowed;
If is too small, the injection flow 20 of the molten metal will hit the endless belt, damaging it and damaging the surface quality of the metal plate lO, which is not preferable.

[Problems to be Solved by the Invention] As mentioned above, the twin-drum continuous metal ribbon casting machine can produce thin metal sheets, but it is not easy to achieve high productivity, and Although belt-type metal continuous casting machines can achieve high productivity by arranging pulleys 19-1 and 19-2 at a large distance, for example in FIG. 6, it is not easy to manufacture thin metal plates.

The present invention was made in order to solve the problems of the prior art, and is a continuous metal ribbon that can manufacture thin metal strips with high productivity and control the thickness distribution of the metal strip with high precision. The company provides casting machines.

[Means for Solving the Problems] As shown in the drawings, the metal ribbon continuous casting machine according to the present invention for achieving the above object has an inclined caster between an upper roll 2.2 and a lower roll 3.3'. It has endless belts 1 and 1' that run as if to form the long side walls of the upper wide mold, and has a mechanism that allows the lower rolls 3 and 3' to intersect when viewed from within the surface of the slab plate,
By manipulating this intersection angle, the thickness distribution of the metal ribbon taken out from the gap between the endless belts 1 and 1' at the lower end of the mold is controlled.

[Function] In the present invention, the pool part between the endless belts forms an upper wide mold, and the lower rolls that determine the slab thickness can intersect when viewed from within the slab plate surface. The plate crown of the slab can be controlled, thereby making it possible to control the plate thickness distribution.

[Example] The present invention will be described below based on an example shown in the drawings. 1st
The figure is a schematic diagram showing the entire continuous metal ribbon casting machine of the present invention, (A) is a side view, and (B) is a cross section along X-X and Y-Y.
A diagram in which the cross sections are superimposed, (C) is a 2-2 cross-sectional view, (D)
is a sectional view taken along line W-W.

The continuous ribbon casting machine of the present invention includes an endless heddle 1 between an upper roll 2 and a lower roll 3, which runs inclined in the direction of an arrow 5;
Upper roll 2' and lower roll 3' placed facing this
An endless belt 1 running in the direction of arrow 5' with an inclination between
' forms the long side surface of the inner wall of the upper wide mold. In the present invention, the endless belts 1 and 1' are stretched under tension, for example, by guide rolls 8 and 8'. 7
and 7' are side weirs, which are, for example, upper wide molds along the running direction of the endless belts 1 and 1', and are sandwiched between the endless belts to form short sides of the inner walls of the upper wide mold. The molten metal is injected into the trough 9, but the back side of the endless belt 1 (1') is connected to the cooling device 4 (
4'), the molten metal solidifies on the endless belt to form a solidified shell, which coalesces at the lower end of the mold to form the metal ribbon 10.

The thin strip continuous casting machine of the present invention differs from the twin-drum continuous thin plate casting machine described above in that the upper roll 2 (2') and the F roll 3 (3') are provided with a sufficient distance between them. Therefore, even when casting at a high speed, a sufficiently thick solidified shell can be obtained to produce a metal ribbon of a predetermined thickness. Furthermore, the continuous ribbon casting machine of the present invention differs from the previously-known twin-belt type continuous ribbon casting machine, in that the molten metal is injected into a large basin at the top, so it is possible to cast thin metal strips. During casting, the flow of molten metal hits the endless belt,
There is no possibility of damaging the endless belt or damaging the surface of the thin metal strip 10.

In the continuous ribbon casting machine of the present invention, when the solidified shells grown independently on the belts 1 and t' are combined, the rolls 3 and 3' press the solidified shells through the endless belts 1 and 1'. This pressurization adjusts the thickness distribution and surface properties of the metal ribbon 10.

With this apparatus, a thin metal strip can be produced that has a small thickness and requires a small amount of reduction in the thickness direction during rolling in the subsequent process. However, at this time, it is important to accurately control the dimensions and shape of the metal ribbon so that it is suitable for the subsequent rolling process. For example, a metal ribbon whose cross section has a crown or a concave crown that is not suitable for subsequent rolling is not a preferable rolled material because flatness defects such as mid-elongation and undulations occur in the thin plate after rolling.

Therefore, when producing thin metal strips, it is necessary to precisely build in the plate crown required from the subsequent rolling process.

The continuous ribbon casting machine of the present invention has a structure in which the lower rolls 3 and 3' that press the solidified shell can cross each other. Figure 1 is an example, showing the X-x cross section and the Y-
It shows a state in which the lower roll 3 and 3' intersect at an angle 2θ as seen in the Y cross-sectional view.

The intersection angle of the lower roll can be set, for example, by using the chock 22a of the lower roll 3, as shown in FIG.

The chock presser 23a can control the position of the chock holder 22b.

23b, 23c, and 23d, and at the same time, the chock position of the lower roll 3' is changed in the opposite direction. In the example shown in FIG. 1, the lower roll 3 intersects within the plane of the belt 1 stretched between the upper roll 2 and the lower roll 3, and the lower roll 3' crosses the upper roll 2' and the lower roll. The structure is such that the belts 1' intersect within the plane of the belt 1' stretched between the belts 3'. In other words, the movement of the lower roll chock is as shown in Figure 1 (
A) in the direction of arrows 6 and 6'. With this configuration, it is possible to cross the rolls without interfering with the side weirs. In addition, by crossing the lower rolls in this way, there is a risk that the tension applied to the belt 1 (1') will become uneven between the working side and the driving side. 8
') can be avoided by making the support mechanisms independent on the working side and the driving side and controlling them so that the same tension always acts on the working side and the driving side. By the way, in this casting machine, it is important to pressurize the solidified shell, and in order to quickly control this pressurizing force even during casting, in the apparatus shown in Fig. 1, the entire lower roll 3 (3') is Arrow 6 (
It is preferable to have a mechanism that can move in the direction 6').

FIG. 2 is an explanatory diagram of the principle by which the plate thickness distribution of the slab can be controlled by changing the intersection angle of the lower rolls as described above. Figure 2 (A) shows the roll cross-sectional position and roll gap h W at the working side slab plate end position when the lower roll 3.3' is crossed by the intersection angle 2θ as shown in Figure 1 (B). ', and the roll gap hc at the center position of the slab plate, and FIG. roll gap h
It is a figure showing c. Note 1. Practically speaking, a very small value of around 1' is sufficient for the roll crossing angle, so it is considered that the belt is always in contact with the lower roll due to the reaction force within the range where the slab is pressurized. Therefore, the second
In the figure, the belts 1 and 1' are each shown integrally with the lower roll. In Fig. 2(A), by taking the intersection angle 2θ, 3c,
The cross section of the lower roll, which was at the position 3c', becomes the position 3w, 3w' at the working side plate end position. The amount of movement U of the cross-sectional center of the lower roll 3.3' at this time is calculated by the following formula, where b is the slab plate width.

u=(b/2) tanθ ・(
1) Therefore, in this case, when the angle between the side surface of the side weir, which is the moving surface of the lower rolls 3 and 3', and the vertical line is φ, the minimum gap at the plate end position, i.e., is the belt thickness. When the apparent lower roll radius is R, it is calculated by 4 using the following equation.

...(2) By substituting equation (1) into equation (2), the following equation is obtained.

...(3) In exactly the same way, hd=h1 can be obtained from FIG. 2(B). From the above, it can be seen that by setting the crossing angle to 20, the plate crown of the slab changes in the negative direction by the amount calculated by the second term on the right side of equation (3) compared to the case of crossing. Therefore, if you give the lower roll 3.3' a concave crown in advance so that the slab sometimes has a convex crown during cross-cutting, you can freely change the thickness distribution of the slab from a convex crown to a concave crown. It becomes possible to control the Further, from equation (3), it can be seen that in order to control the slab thickness distribution, which is the objective of the present invention, it is a necessary condition that φ<90°. When φ〉90”, no pool can be formed, and when φ=90°, the formula (
3) The second term on the right side is always zero, and the effect of controlling the plate thickness distribution due to the intersection of the lower rolls is completely eliminated. φ〈90
When the lower rolls are crossed in a state of 10°, it is possible to observe whether the rolls are crossed by looking from inside the plate surface of the metal ribbon 10, and this is a necessary condition of the present invention.

FIG. 3 shows another structure of the continuous ribbon casting machine of the present invention. The apparatus shown in Fig. 3 has a cast slab lO by belt 1 (1') below lower roll 3 (3') while keeping the distance between belts l and 1' determined by lower rolls 3 and 3' almost constant.
5 cooling devices 14 (14
') and Gaitrol 12 (+2') are equipped. The guide roll 12 (12') is the lower roll 3 (3
It is configured to be movable in the direction of the arrow 13 (+3') in accordance with the movement of the slab 10 (+3'), and it is also possible to slightly pressurize the slab 10 by the guide roll 12 (12'). However, it is the lower roll 3 (3') that presses the solidified shells formed on the endless belts 1 and 1', and therefore, during regular work except at the start of casting, there is no side weir below the lower roll. Basically not necessary. By extending the cooling area by the belt 1 (1') in this way, the range of cooling rates that can be selected as a means of controlling the material quality of the slab is expanded, and even during unstable operations such as at the start of casting, This is a mechanism that is less likely to cause problems such as slab breakage. In addition, when there is no longer a need for rapid cooling after casting using the casting apparatus shown in FIG.
(1') should not come into contact with the slab.

FIG. 4 shows still another structure of the continuous ribbon casting machine of the present invention. In the apparatus shown in FIG. 4, the body length of the lower roll is slightly shorter than the width of the slab plate, so that the lower roll 3 ( The chock 3') can be moved to cross the lower rolls 3 and 3'. In this case, the relationship between the intersection angle 2θ and the change in thickness distribution of the slab is given by setting φ=0 in equation (3). Further, in this apparatus, in order to control the pressing force applied to the slab by the lower roll 3.3', it is preferable that the lower roll is configured to be movable in the thickness direction of the slab. In response to such movement of the lower rolls 3 and 3', the side weir 7' prevents hot water from leaking through the belt by side holders 17 and 17' to prevent hot water from leaking between the side weir and the belt. Although it is not shown, it is lightly pressurized to the extent that it does not
The side weir 7 on the working side (front side) is also supported by four side supports. The pressing force of the side weir is, for example, the side holding moving device 16a (I[ia') and +6b
(16b'). Further, it is preferable that the side weir 7 (7') be configured to be movable up and down so as to be able to cope with large movements of the lower roll 3 (3') in the slab thickness direction.

[Specific Example of the Invention] Using a casting device having a structure as shown in Fig. 1, a belt thickness of 1 mm, and a belt width of 800+nn+,
Molten steel having a stainless steel composition of 04 at a temperature of 1,490°C was poured into a tundish, and a plate with a wall thickness of 2 mm and a plate width of 6001111 was poured.
! 1 of metal ribbons were produced. Lower rolls 3 and 3' have a diameter of 30oI! 1III, and is constructed so that the chocks can be moved and crossed in the directions of the belt planes, that is, the directions of arrows 6 and 6', each inclined at 15 degrees with respect to the vertical line, as shown in FIG. When casting was carried out with a concave crown of 220 μm/diameter provided on the lower rolls 3 and 3' of body length 9001, a slab having a convex crown of about 100 μm was obtained. Therefore, as shown in FIG. 1(B), casting was carried out by intersecting the lower rolls at an angle 2θ = 1.5°, and a cast slab with a flat plate crown was obtained.

[Effects of the Invention] By using the continuous metal strip casting machine of the present invention, thin metal strips can be manufactured with high productivity, and the metal strip can be accurately controlled into a shape suitable for rolling in the next step.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the overall structure of the present invention, FIG. 2 is a schematic diagram explaining the basic principle of the present invention, FIG. 3 is a diagram showing another structure of the present invention, and FIG. 4 is a schematic diagram showing another structure of the present invention. Diagrams showing different structures,
FIG. 5 is a diagram showing a known twin-drum continuous metal ribbon casting machine, and FIG. 6 is a diagram showing a known twin-belt continuous metal ribbon casting machine. 1.1': Endless belt, 2.2': Upper roll, 3°3'
: Lower roll, 4.4': Cooling device, 6.5': Belt running direction, 6.6': Lower roll chock moving direction, 7.7
': Side weir, 8.8' Ni guide roll, 9: Hot water pool,
lO: Metal ribbon, 11: Molten metal, 12 Ni guide roll, 1
3. Direction of movement of two guide rolls, 14: Cooling device, 15. Two guide rolls, 16. Two side weir press moving device, 17: Side holding, 113 (113-1, 18-2>: Rotating drum, 19 (19-1, 19-2, 19-3, 19'
-1,19'-2,19'-3): Pulley, 20: Molten metal injection flow, 21.21': Cooling device, 22 (22a
, 22b): Lower rollch B''/ri, 23 (23a
, 23b. 23c, 23d) Nichoku presser foot◇

Claims (1)

[Claims] 1. Upper rolls (2), (2') and lower rolls (3), (3
It has endless belts (1) and (1') that run inclined between the upper rolls (1) and (1') and form the long side walls of the upper wide mold;
and (3') intersect when viewed from within the surface of the slab plate, and by manipulating this intersecting angle, the gap between endless belts (1) and (1') at the lower end of the mold is reduced. A continuous metal ribbon casting machine that controls the thickness distribution of the metal ribbon taken out from the machine.