JPS61219445A - Horizontal and continuous casting method - Google Patents

Abstract

PURPOSE:To cut exactly a continuously cast ingot to a prescribed desired length by controlling the weight value of the continuously cast ingot after cutting, the drawing and stopping of the steel ingot at the temp. in each part before cutting and the position of a cutter in the stage of drawing and stopping intermittently the continuously cast ingot and cutting the continuously cast ingot to the prescribed length with a horizontal type continuous casting device. CONSTITUTION:The molten steel in a tundish 30 is cast into a mold 31 and is cooled by a break ring to form a discontinuous part continuous with the peripheral direction of the continuously cast ingot, then the continuously cast ingot is intermittently drawn in a direction B1 by guide rollers 36. The ingot 32 is cut to the prescribed length by a cutter 37 in the down stream direction. The temp. in each part of the ingot 32 before cutting is measured and is inputted together with the weight value 44 of the cut ingot into a control device 46. The length of the ingot 32 changes with a weight difference upon shrinkage by cooling and therefore the cutting of the continuously cast ingot always to the desired length is made possible by changing the rotating speed and direction of ingot conveying rollers 34, 35 and moving the position of the cutter 37 by a position corrector.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a horizontal continuous casting method that is suitably used, for example, in producing forged materials.

BACKGROUND ART FIG. 16 is a sectional view of a prior art horizontal continuous casting apparatus 1. The horizontal continuous casting apparatus 1 includes a tundish 2 and a mold 3. Molten g A, 6 is stored in a space 5 formed by a fireproof wall 4, which is an inner wall surface of the tandish 2. Further, a tundish nozzle 9 having a hole 8 for flowing molten steel 6 into the mold 3 is provided near the bottom 7 of the tundish 2.

When the tundish nozzle 9 and the mold 3 are opened, a connecting ring 12 and a break ring 13 having holes io, ti coaxial with the axis of the tundish nozzle 9 are arranged in this order from the tundish 2 side. Ru.

The mold 3 has an inner cylinder 1 that contacts the molten fa6 and cools it.
4, and an outer *16 which is coaxial with the inner cylinder 14 and forms a space 15 between the inner cylinder 14 and the inner cylinder 14.

Furthermore, a partition member 17 is provided in the space portion 15 . The partition member 17 includes a right cylindrical portion 18 coaxial with the inner cylinder 14 and a support member 19 provided along the circumferential direction on the outer periphery of the right cylindrical portion 18 . The foreign bond 16 also includes an inlet 20 for injecting cooling water into the space 15 and an outlet 2 for discharging the cooling water.
1 is provided.

The molten steel 6 flowing into the mold 3 from the tundish 2 is cooled by the inner cylinder 14, the break ring 13, etc., and solidification starts from the outer peripheral surface, forming a solidified shell 22. The slab 23 thus obtained by cooling and solidifying is pulled out along the axial direction of the mold 3 in a direction opposite to the tundish 2.

The drawn slab 23 is cut by a hot or cold gas cutting machine,
It is cut to the desired length using a hydraulic shear, mechanical shear, saw, abrasive cutter, etc. In such a cutting operation, when a spacing cutter, an abrasive cutter, a saw, or the like is used, there is a problem in that the cutting allowance is large and the yield of the product is poor.

Furthermore, although the yield can be improved by using a mechanical shear, there are the following problems.

■The load associated with cutting is large. ■The deformation of the cut part is large.

■Cracks occur near the cut surface during cutting. This problem of cracking becomes noticeable when the slab 23 is cold cut.

If an extremely short cutting length of the slab 23 is required, the cutting time must also be shortened, and a large cutting device may be required.
I had to. Therefore, in the prior art, the interval between the parts where the slab 23 is cut is set at 1500τn, for example.
It was cut once at ``un'' and then further shortened to one length.

Problems to be Solved by the Invention Therefore, in the prior art as described above, when attempting to cut the slab 23 into short dimensions, the configuration of the device required for cutting becomes large, and a complicated process is required. There were problems such as.

SUMMARY OF THE INVENTION An object of the present invention is to provide a horizontal continuous casting method that solves the above-mentioned problems and allows slabs of a desired length to be obtained through a simplified process.

Means for Solving the Problems The present invention intermittently pulls out and stops the slab, and cools the break surface formed in the vicinity of the downstream end of the connecting ring in the drawing direction by cooling means. This is a horizontal continuous casting method characterized by cooling and forming discontinuous portions extending in the circumferential direction of the slab in the cooled portion by the break surface of the slab.

When taking out the working slab from the mold, drawing and stopping are performed intermittently. At this time, a break surface connected to the mold is formed near the downstream end of the connecting ring in the pulling direction,
This breaking surface is cooled by a cooling means. A discontinuous portion extending in the circumferential direction of the slab is formed in a portion cooled by the break surface of the slab. Since the slab in which such a discontinuous portion is formed becomes thinner at the discontinuous portion, the slab taken out from the mold can be easily cut at the discontinuous portion. Furthermore, by controlling the length between these discontinuous portions, the slab can be cut to the desired length.

Embodiment PttJj is a system diagram of an embodiment of the present invention. A molding V31 serving as a cooling means is fixed to the tundish 30. The piece 32 is pulled out from the mold 31 in the following manner 611) The piece 32 is pulled out by the guide roller 36a.
t36b, . . . , 36c (collectively referred to as 36). The drive motor 33 moves the arrow A1. Pulling rollers 34 u, 34 b: 3 rotated in A2 or arrow A3 and A4 directions, respectively.
5a, 351) (collectively referred to as 34.35), the slab 32 is pulled out in the direction of arrow B1.

In this pulling operation, the pulling rollers 34, 35,
Arrow A1. Rotate in direction A3, stop, arrow A2. An intermittent pulling operation is performed with rotation in the A4 direction and a cycle of stopping. For each of these pulling operations, a cold shut, which is a discontinuous portion, is formed as will be described later.

A cutting device 37 is arranged on the downstream side in the drawing direction with respect to the drawing rollers 34=35. The cutting device 37 is supported by wheels 38a and 38b (collectively referred to as 38) and has three casings that are movable in directions B1 and B2. The cutting device 37 is moved by the arrow B by a position correcting device 40 consisting of, for example, a hydraulic cylinder.
It is moved in the l and B2 directions. The cutting device 37 includes a drive such as a hydraulic sill for driving the cutting blades 41 and 42.
A device 43 is provided. The cutting device 37 performs the cutting operation during the stop period when the slab 32 performs the intermittent drawing operation as described above.

A weighing device 44 is disposed downstream of the cutting device 37 in the drawing direction to weigh the cut slab. The weight of the slab cut by the cutting device 37 is measured by the weighing device 44.

Further, the radiation temperature of each part of the slab 32 after being pulled out from the mold 31 and being weighed by the weighing device 44 is measured by radiation thermometers 45a, 45b, and 45e (collectively referred to as 45). A signal from the radiation thermometer 45 is given to a control device 46.

Further, a signal related to the weight of the cut slab 32 weighed by the weighing device 44 is given to the control device 46 . The slab 32 is cut to a desired length by the cutting device 37, but by the time the slab 32 is pulled out of the mold 31 and reaches the cutting device 37, the slab 32 is cooled and shrinks. Therefore, the control device 46 controls the drawing roller 3 based on the weight of the cut slab 32 weighed by the weighing device 44 and the shrinkage rate accompanying cooling of the slab 32.
4 and 35 are calculated, and the manner of rotation is controlled. The control device 46 also controls the cutting device r!
137 is driven, and the cutting device 37 is moved in the direction of arrow B1 or B2. In this way, the slab 32 can be cut to a desired length.

Here, the length of the cutting device 37 and the mold 31 is the length between the end of the break ring inside the mold 31 in the arrow B1 direction and the cutting position of the cutting device 37, which will be described later.

Since this length L is set as a multiple of the drawing ffl, 5l-82, the cutting position can be controlled with high precision.

FIG. 2 is a sectional view of the vicinity of the mold 31 in FIG. 1. The structure around the mold 31 will be explained in more detail with reference to FIG. There is a fireproof wall 4 inside the Tanditshu 3°.
7 is stretched. Space 48 surrounded by fireproof wall 47
Molten steel 49 is stored in. Further, an iron skin 5° is provided surrounding the fireproof wall 47.

The tundish 30 has a hole 52 near the bottom 51 for guiding the molten steel 49 to the outside of the tundish 30,
A tundish nozzle 53 made of ceramic or the like is provided. The tundish nozzle 53 and the mold 31 are connected via a mounting member 54 made of a heat-resistant material and a connecting ring 56 having a hole 55 through which molten steel 49 flows, in this order. The tundish nozzle 53 and the connecting ring 56 are made of heat-resistant material, and the holes 52 and 55 are
The inner circumferential surface of is formed into a continuous right cylindrical shape. The outer circumferential surface 57 of the connecting ring 56 includes a right cylindrical surface 58 , a protruding portion 59 that projects in the radial direction along the circumferential direction of the connecting ring 56 , and a protruding portion 59 that extends from the tundish 30 side.
A tapered surface 57 that tapers away from o
It consists of.

-8= The mold 31 connected to the connection ring 56 includes an inner tube 61 made of copper, for example, and an outer tube 63 that forms a space 62 between the inner tube 61 and the inner tube 61 . Tandish 3 of inner cylinder 61
The vicinity of the end on the 0 side is bent radially inward. The shape of the radially inner end surface 65 of this bent portion 64 of the inner cylinder 61 corresponds to the tapered surface 57 of the connecting ring 56, and these are assembled with each other. Furthermore, a partition member 66 is arranged inside the space 62. The partition member 66 is connected to the inner cylinder 6
1, and a support member 68 provided along the outer periphery of the cylinder 67 in the circumferential direction. Further, the outer cylinder 63 is formed with an inlet 69 for cooling water that circulates within the space 62 and cools the inner cylinder 61, and a discharge lower 0 that discharges the cooling water. Further, the connecting ring 56 and the mold 31 are connected by a connecting member 71.

The molten steel 49 that has flowed into the mold 31 from the inside of the tundish 30 is cooled by the inside 1:161 and solidified from the outside in the radial direction, thereby forming the solidification shelf 2. The thus cooled molten gA49 is extracted from the mold 31 as a slab 32.

FIG. 3 is a graph illustrating the drawing operation of the slab 32 described with reference to FIG. 1, and FIG. 4 is a sectional view of the mold 31 illustrating the cooling state of the molten a49. The operation of the apparatus shown in FIG. 1 will be described with reference to FIGS. 1 to 4. According to a signal from the control device 46, at time t1, the drive motor 33 moves the drawing rollers 34, 35 to the arrow mark Al.

It rotates in the A3 direction and stops at time t2. That is, the area S1 of the region 73 shown with diagonal lines in FIG.
is the amount of displacement of the slab 32 in the direction of arrow B1 from time t1 to t2.

At time t3, the pulling rollers 34 and 35 move in the direction of arrow A.
2. It is rotated in the A4 direction. Therefore, the area S2 of the shaded region 74 in FIG. 3 is the displacement amount by which the slab 32 is pushed back in the direction of arrow B2. Next time t2
~t3+t4~t5, the pulling roller 34.3
5 is stopped. In this embodiment, from time t1 to (5
The above-mentioned intermittent drawing operation is performed on the slab 32 during the -cycle. Therefore, mold 31
The axial length Ll of is made larger than the value of 5l-82.

Further, the displacement amount 5l-82 of one cycle of the drawing operation is set to be slightly longer than the desired length of the slab 32 to be cut. That is, as described above, since the slab 32 is cooled and contracts, the length of the slab 32 in the axial direction is reduced to a desired length in advance. Here, when the cutting device 37 cuts the slab 32 when it is stopped, the cutting is performed at time t2 to t3 or from time 4 to L5.

With reference to FIGS. 3 and 4, the four solidification processes of molten steel will be explained. The state of solidification of molten g449 at time 1 is shown in FIG. 4 (1). Inner peripheral surface 75 of inner cylinder 61
The inner peripheral surface 75 of the part parallel to the TLJJ line of the mold 31
The four molten steels are cooled by a.

In the cooled molten steel 49, a solidified portion 76 shown with diagonal lines increases in thickness from radially outward to inward.

On the other hand, the end surface of the bent portion 64 of the inner cylinder 61 in the arrow B1 direction is
This is a break surface 77 that contacts the molten steel 49 and cools it. The molten steel 49 is also cooled by this break surface 77, and therefore solidification progresses into the shape of the solidified portion 76 in FIG. 4(1).

One displacement of the slab 32 in the direction of arrow B1 ends at time t2. The solidification states of the four molten steels at time t2 are shown in FIG. 4(2). That is, the end surface 76a of the solidified portion 76 on the break surface 77 side is displaced by a distance as1 in the direction of arrow B1. The molten steel 49 between the end surface 76a and the break surface 77 is cooled by the inner cylinder 61 and the break surface 77. Therefore, solidification is started into the shape shown in FIG. 4(2).

At this time, as described above, the end surface 76n of the solidified portion 76 is sufficiently cooled by the break surface 77, so that it does not weld with the newly flowing molten metal 49. Therefore, a coal shut 79 is formed on this end surface 76a.

At time 3, arrows B1 and B on coagulation shelf 2
There is no displacement in two directions, and as shown in FIG. 4 (3), a new solidified portion 8 is formed between the solidified portion 76 and the break surface 77.
0 grows.

The state of the slab 32 at time t4 is shown in FIG. 4 (4). At this time, the slab 32 is pushed back in the direction of arrow B2. This pushing back operation cools the molten g449 and compensates for the shrinkage. That is, due to this shrinkage, a gap may be formed between the solidification shelf 2 and the break surface 77 or the inner cylinder 61, and such a gap deteriorates the quality of the surface shape of the obtained slab 32. Therefore, the surface shape is improved by such a push-back operation in the direction of arrow B2. The new solidified portion 80 grows further radially inward.

At time t5, the new solidified portion 80 grows further radially inward, as shown in FIG. 4(5).

Meanwhile, the solidified portion 76 also grows radially inward.

In this way, the radial thickness of the solidification shelf 2 is
Basically, it increases as it moves away from the break surface 77. In this way, the slab 32 is formed.

As described above, the hook piece 32 extracted from the mold 31
In this case, a cold shut 79 is formed every displacement distance S1 of the extraction operation of the slab 32. Therefore, the length L2 of the slab 32 after cutting is 8, and the distance S
1-82. At this time, the slab 32 can be easily cut by cutting the cold shut 79 portion using the cutting device 37.

If the material of the slab 32 to be cast is a material that is prone to cracking, such as cast iron or chromium-based alloy steel, it can be cut by hitting the vicinity of the cold shut 79 with, for example, a hammer, without using the cutting device 37. , slab 32
may be cut.

FIG. 5 is a front view of a cutting device 37 according to still another embodiment of the present invention. This embodiment is similar to the previous embodiment, and corresponding parts are given the same reference numerals.

The noteworthy point of this embodiment is that the cutting device 37 is
Support rollers 81 and 82 that support 2 and support roller 81
, 82 with respect to the slab 32. ．． Suppression row 2 located on the opposite side from 82
83. In this embodiment, the slab 32 is supported by support rollers 81 and 82 so that the cold shut 79 is included in a vertical plane that includes the axis of the pressure roller 83. Next, by pressing down the pressing roller 83 in the direction of arrow C, the slab 32 is moved to the cold shut 79.
VOR is performed in that part. Even with such a cutting device 37, the same effects as those described in the above-mentioned embodiments can be obtained.

FIG. 6 is a sectional view of still another embodiment of the present invention. This embodiment is similar to the previous embodiment, and corresponding parts are given the same reference numerals. A noteworthy feature of this embodiment is that, independent of the mold 31, it has a break surface 77 and is provided with a break ring 84 made of, for example, copper. A space 85 is formed in the break ring 84 to receive cooling water. A partition member 86 is provided in the space 85 to efficiently circulate cooling water. Cooling water is injected from the inlet 87 , circulates through the space 85 to cool the break ring 84 and the break surface 77 , and is then discharged from the outlet 88 . The second noteworthy point of this embodiment is the axis of the upper half of the connecting ring 56.

A difference δ of, for example, about 0.2 to 2IIIa is provided between the length in the direction and the length in the axial direction of the lower half.

By configuring the break ring 84 as described above, the cooling efficiency of the break surface 77 can be further improved. Also, as mentioned above, the brake ring 84
By providing the above-mentioned difference δ regarding the structure of the slab 3
The cold shut 79 formed on the outer periphery of the slab 3
The positions of the upper and lower halves of 2 will be shifted. A slab 3 in which such a cold shut 79 is formed
2 is, for example, the cutting device 37 described with reference to FIG.
cutting becomes easier.

Even with such a configuration, the same effects as those described in the previous embodiment can be obtained, and the configuration of this embodiment also makes it possible to eliminate the need for castings having a larger diameter cross section. , can be implemented more advantageously.

FIG. 7 is a cross-sectional view of still another embodiment of the present invention, and FIG. 8 is a cross-sectional view taken along the section line ``---'' in FIG.

This embodiment is similar to the previous embodiment, and corresponding parts are given the same reference numerals. What is noteworthy about this embodiment is that the break ring 89 having the break surface 77 is made of a heat-resistant material such as ceramics, and that a cooling means 90 for cooling the break ring 89 is provided. The cooling means 90 is similar to the grooves in the break ring 84 of the embodiment described with reference to FIG. The second example of this example
What should be noted is that a space 91 is formed between the connection ring 56 and the cooling means 90 along the circumferential direction of the connection ring 56, and a space 91 is formed between the break ring 89 and the inner cylinder 61 in the radial direction. This is because a space 92 forming a gap is formed.

In each of the above embodiments, the molten g A, 49 that has flowed into the mold 31 is rapidly cooled and the cold shut 79 is closed.
is formed, and by this cold shut 79, the slab 3
2 was made easier to cut. On the other hand, by using a configuration in which the melt @49 is rapidly cooled, the following problems may occur.

■Since the molten steel 449 is rapidly cooled by the connecting ring 56, it causes blockage in the hole 55. ■Because the molten steel 49 is rapidly cooled by the break surface 77, etc., there is no directionality near the tips of the seven cold shuts. Fine internal cracks may occur.

■Because the cooling capacity of the connecting ring 56 and the break surface 77 is excessive, there is a risk that the solidified portion 76 will r&i the inner surface of the connecting ring 56. required.

(2) When a slab 32 with a complicated cross-sectional shape is required, the shape of the inner cylinder 61 of the mold 31 is configured to match the cross-sectional shape of the slab to be obtained. At this time, the temperature distribution of the connecting ring 56, the break rings 84, 89t-+, and the inner cylinder 61 becomes uneven, and for example, the break ring 8 shown in FIG.
4 and the inner cylinder 61, the break ring 84, the inner cylinder 61, etc. may be deformed, and the boundary surface 93 may be deformed.
A gap will be created between the two.

These supposed problems can be solved as follows. Due to the space 91 formed in this example, debris with low thermal conductivity is formed between the connecting ring 56 and the cooling means 90, so that the four molten steels are excessively cooled by the connecting ring 56. Occurrence of blockage in the hole 55 can be prevented.

Further, the break surface 77 is formed by eight break rings made of a material with low thermal conductivity. Therefore, it is possible to prevent the molten steel 49 from being overcooled by the break surface 77, and it is possible to prevent the formation of internal cracks caused by overcooling.

By providing the space g91 and the eight break rings, it is possible to prevent excessively rapid cooling of the melt gA49. Therefore, the speed at which the slab 32 is pulled out can be appropriately selected. That is, the above-mentioned pulling rollers 34, 35
(See Figure 1) should not be performed at an unnecessarily high speed.

Also, by providing the space 92, the break ring 8
9 and the inner cylinder 61, problems caused by temperature distribution are improved. On the other hand, even if the degrees of expansion or contraction differ, this space 9
2 so that the length in the radial direction is long. Therefore, the above-mentioned supposed problem (2) is solved.

@ Figures 9 and 10 are simplified cross-sectional views of molds of other embodiments. Inner cylinder 6 of mold 31 shown in FIG.
The shape of the inner cylinder 61 is not limited to a circular shape as shown in FIG. 8, and special-shaped inner cylinders 61 as shown in FIGS. 9 and 10 may also be used. As mentioned in the previous example,
In the drawing operation of the slab 32, one cycle of the drawing operation constitutes one product, so the problem of forming a cold shut due to the intermittent drawing operation is solved. Therefore, the diameter and shape of the hole 55 of the connecting ring 56 can be set arbitrarily. That is, in the slab 32 obtained by cooling, if the cross-sectional area of the cold shut 79 portion is large enough to load the driving force for the drawing operation, and at the same time does not cause blockage of the molten steel 49 in the hole 55. , the diameter and shape of the hole 55 etc. can be set arbitrarily.

Therefore, even when forming a slab 32 having a special cross-sectional shape as shown in FIGS. 9 and 10, the holes 55 for supplying the four molten steel can be made small in diameter, and the holes 55, etc., for supplying the four molten steel can be made small in diameter, and can be made in a simple shape such as a circular shape. It can be made into a shape.

FIG. 11 is a sectional view of the vicinity of the mold 31 of still another embodiment of the present invention, and FIG. 12 is a sectional view of the slab 31 in this embodiment.
2 is a graph illustrating the intermittent pulling operation of No. 2. This embodiment is similar to the previous embodiment, and corresponding parts are given the same reference numerals. In the horizontal continuous casting apparatus 1 of the prior art described with reference to FIG. may become extremely small, resulting in so-called hot spots. Such hot spots are one of the factors that reduce the quality of the slab 23.

Therefore, the drawing operation during period W is controlled in the manner shown by line No. 1 in FIG. That is, from time t6 when the second half of the pulling operation starts to time L7, arrow B1
Gradually reduce the pulling speed in the direction. Then time t
After continuing the pulling operation in the direction of arrow B1 at a low speed during the period from 7 to t8, the pulling operation is ended at time t2. By performing the drawing operation in this manner, it is possible to reliably prevent the occurrence of hot spots as described above due to cooling of the slab 32.

FIG. 13 is a sectional view of the vicinity of the mold 31 of still another embodiment of the present invention. , this embodiment is similar to the previous embodiment, and corresponding parts are given the same reference symbols. The noteworthy point of this embodiment is that the thickness of the coagulation shelf 2 between the cold shuts 79 is made as uniform as possible between the cold shuts 79.

In the outer circumferential surface 61b of the inner cylinder 61, a recess 94 is formed along the circumferential direction at a distance from the break surface 77 that is smaller than the non-pulling displacement amount S1. Therefore, the inner cylinder 6 in the recess 94 portion
The radial thickness B3 of the inner cylinder 61 is smaller than the thickness B4 of the remaining portion of the inner cylinder 61.

That is, the cooling rate of the molten steel 49 cooled by the inner tube 61 in the recess 94 portion is higher than the cooling rate in the remaining portion of the inner tube 61.

Further, recesses 95a95b, . . . (
(collectively referenced 95). This recess 9
5, heat insulating layers 96a, 96b, . . . (collectively referred to as 96) made of, for example, graphite or ceramic are formed. Therefore, each portion of the solidification shelf 2 facing the heat retaining layer 96 is slowly cooled. Therefore, the above-mentioned recess 94 and the heat insulation W! 96, the thickness between each cold shut 79 of the coagulation shelf 2 can be made as uniform as possible.

In this way, each cold store 7179 of the coagulation shelf 2
By making the thickness as uniform as possible, the above-mentioned hot spots will not be formed and a slab 32 with good internal quality can be obtained.

FIG. 14 is a simplified front view of a horizontal continuous casting apparatus 1 according to yet another embodiment of the present invention.6 This embodiment is similar to the previous embodiment, and corresponding parts are given the same reference numerals. . What is noteworthy about this embodiment is that the tundish 30 and the raised mold 31 are supported by elastic support means 97 such as a spring, and are equipped with a vibration generator 98.

This vibration generator 98 is provided with an arrow *B 1 along the axial direction of the mold 31 in the tundish 30 and the mold 31.
t B Vibration in two directions, or arrow C along the vertical direction
1. Gives vibration in the C2 direction. By applying such vibration, seizure can be prevented from occurring between the mold 31 and the slab 32. This embodiment can be suitably implemented when casting a so-called long object.

FIG. 15 is a system diagram of a horizontal continuous casting apparatus 99 according to still another embodiment of the present invention. This embodiment is similar to the previous embodiment, and corresponding parts are given the same reference numerals. The noteworthy point of this embodiment is that an electrode immersed in the melt 49 inside the tundish 30 and an auxiliary electrode 101 in contact with the slab 32 outside the mold 31 are provided. These electrodes 100
Power is supplied to the auxiliary electrode 101 from the power supply device 102 . Further, temperature detection means 103 for detecting the surface temperature of the slab 32 is provided between the mold 31 and the auxiliary electrode 101. The signal from the temperature detection means 103 is sent to the arithmetic unit M
104 , the computing device 104 decreases or increases the output of the power supply 102 .

The current flowing between the electrode 100 and the auxiliary electrode 101 is generated at the connection between the mold 31 and the tundish 30.
Hole 5 of tundish nozzle 53 and connecting ring 56
Flows through melt @49 within 2,55. Since the diameter L3 of the holes 52 and 55 is smaller than the diameter L4 of the inner cylinder 61 of the mold 31, the maximum Joule heat within the mold 31 is generated at the holes 52 and 55. This Joule heat can prevent the holes 52 and 55 from being clogged due to overcooling of the molten gA49.

The electrode 100 is moved up and down in the vertical direction by a drive device 108 consisting of a pinion 106 that engages with a rack 105 and a drive means 107 that rotationally drives the pinion 106 as the liquid level 49a of the melt @ 49 changes. be able to.

As described above, when the molten steel 49 is cooled and solidified, it contracts. Therefore, during intermittent withdrawal operations, the solidification shelf 2
A gap is created between the inner cylinder 61 and the molten metal 49 flowing into the gap, which may cause a so-called metal drop. In each of the above-described embodiments, this bullion insert has a tapered shape that narrows in the direction away from the tundish 30, for example, from the break surface 77 on the mold inner surface 75 in the pulling direction. This can be solved by providing a taber of ~30%/m.

In each of the above-described embodiments, the slab 32 was subjected to the intermittent drawing and movement described above with reference to FIG. 3, but the so-called return stroke shown by the area 74 in FIG. You don't have to. The return stroke is performed for the purpose of compensating for the shrinkage caused by the cooling of the molten steel 49, but as described above, this shrinkage can be compensated for by, for example, providing the inner cylinder 61 with a tapered taper in the direction away from the tundish 30. This is because that.

In each of the embodiments described above, the slab 32 is cut by the cold shut 79 formed on the outer peripheral surface of the slab 32. Since the cold shut 79 is not formed in the cut slab 32, there is no problem with the quality of the slab 32. Furthermore, by setting the quality of the cut slab 32 as the drawing stroke S1, short slabs can be obtained, and the cutting allowance is 1 call! Since the gap provided by the shaft 79 is sufficient, the yield is greatly improved.

Effects According to the present invention as described above, the slab is pulled out from the mold by intermittently pulling out and stopping the slab.

A break surface connected to the mold is formed near the downstream end of the connecting ring in the drawing direction, and this break surface is cooled by a cooling means. By cooling the slab on this break surface, a discontinuous portion along the circumferential direction of the slab was formed. Therefore, with a simplified process, you can produce slabs of the high quality you desire! ! ! It was made to create.

[Brief explanation of drawings]

FIG. 1 is a system diagram for realizing an embodiment of the present invention, FIG. 2 is a sectional view of the vicinity of the mold 31 in the #tJi diagram, FIG. 3 is a graph explaining the intermittent pulling operation of the slab 32, and FIG. The figure is a sectional view of the mold 31 illustrating the state of solidification of the molten steel 49 accompanying this intermittent drawing operation, FIG. 5 is a front view of a cutting device 37 realizing another embodiment of the present invention, and FIG. FIG. 7 is a sectional view of the vicinity of the mold 31 realizing still another embodiment of the invention, FIG. 8 is a sectional view of the vicinity of the mold 31 realizing still another embodiment of the invention, and FIG. ■−■
FIGS. 9 and tA10 are cross-sectional views of the mold 31 of the embodiment having a different cross-sectional shape at 7M, taken along the cutting plane line ■-■, and FIG. 12 is a graph illustrating the intermittent drawing operation of the embodiment shown in FIG. 11, and FIG. 14 is a system diagram according to yet another embodiment of the present invention, and FIG. 15 is a sectional view of the horizontal continuous casting apparatus 99 that realizes still another embodiment of the present invention. FIG. 16 is a sectional view of a prior art horizontal continuous casting apparatus. 30... Tanditshu, 31... Mold, 32
... Slab, 49... Molten steel, 52... Hole, 53.
...Tundish nozzle, 55...hole, 61...
Inner cylinder, 72... Solidified shell, 75... Inner peripheral surface, 77
...Break surface, 79...Cold shut, 34
．． 89...brake ring, 94.95...recess,
99...Horizontal continuous casting device agent Patent attorney Number of strokes Keiichi, 1 l'lJノI ・Ba) 1 1 1 cD) I U) ＾ l, + 1. 1pen Washijo Soft N, go □ 6, 11. . 1-□□ Chiimaichi..., 9 zo...゛□

Claims (1)

[Claims] The slab is drawn out and stopped intermittently, and the break surface formed in the vicinity of the downstream end of the connecting ring in the drawing direction is cooled by a cooling means, and the slab is pulled out. A horizontal continuous casting method characterized by forming discontinuous parts that extend in the circumferential direction of the slab in the part cooled by the break surface.