JP3452799B2 - Continuous casting guide roll device and continuous casting method - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention positively causes bulging of a slab between guide roll groups of a continuous casting facility in order to reduce center segregation of a steel slab cast by a continuous casting method. More particularly, it relates to a guide roll device for continuous casting equipment that can prevent steel leakage at the final stage of casting and improve the casting yield at the initial and final stages of casting.

[0002]

2. Description of the Related Art When a steel slab is manufactured by a continuous casting method, problems such as center segregation and internal cracks which occur in the slab are problems.

The cause of the center segregation is that molten steel in which the constituent elements such as C, Mn, S, and P are concentrated between dendrites at the end of solidification of molten steel remains as it is in the central portion in the thickness direction of the slab. This is because the solidified steel moves in a macroscopic manner toward the solidification completion point of the final solidified portion due to the solidification and the molten steel flow caused by the swelling of the slab called shrinkage during solidification or bulging. Therefore, as a measure for preventing the center segregation, it is effective to prevent the movement of the concentrated molten steel between the dendrites and to prevent the localized accumulation of the concentrated molten steel.

As described above, it has been said that center segregation occurs when bulging occurs in the slab during casting. However, continuous casting method (hereinafter referred to as this A method for preventing the occurrence of center segregation is proposed by the method "bulging-rolling down method".

FIG. 1 is a diagram schematically showing an example of a continuous casting method for explaining the principle of the "bulging-reduction method".

As shown in FIG. 1, molten steel 1 has a dipping nozzle 2
It is poured into the mold 3 which is water-cooled through the solidification shell 4a.
Are formed and pulled out of the mold. The solidification shell 4a is
Further cooled by cooling water sprayed from a spray nozzle group (not shown) provided between the rolls of the guide roll groups 5a and 5b, a cast piece 4 is formed and pulled out by a pinch roll 6.

In the "bulging-reduction method", the guide roll group 5b in the bulging zone is gradually expanded in roll interval, and the solidified shell 4a is moved by the static pressure of the molten steel so that the central portion in the longitudinal direction of the slab is in the short side direction. Spread, so-called bulging occurs. The bulging slab is gradually reduced by the reduction roll group 5c in the reduction zone, and the solidification interface of the slab is pressed and solidified. The solidified slab 4 is pulled out by the pinch roll group 6 in the direction of the arrow.

The bulging zone may be provided with an electromagnetic stirring device 7 for stirring the molten steel in the slab. A reduction device 8 is provided on each of the reduction rolls. The reduction zone may be a pair of reduction rolls 5c.

Next, an example proposed for the "bulging-rolling down method" will be described with reference to FIG.

Liquid layer line crater end 9a of mold 3 and cast piece 4
A bulging force is applied to the solidification shell 4a between the liquid layer line crater end 9a and the solid phase line crater end 9a.
Continuous casting method in which reduction is applied to the slab between and (Japanese Patent Laid-Open No. 60-6
(See Japanese Patent No. 254).

In continuous casting of a slab 4 having a flatness ratio of 1.6 or less, the roll interval is made wider than the inner thickness of the lower end of the mold in a plurality of guide rolls 5a, 5b arranged immediately below the mold 3 in the slab thickness direction. A method for producing a slab in which bulging is performed, and the slab 4 is reduced by 0.04 to 10% by another roll 5c behind the bulging (see JP-A-60-21150).

The guide roll group 5 arranged in the drawing direction from immediately below the mold 3 is gradually increased in the thickness direction of the slab 4 to cause bulging of the slab, and the thickness of the slab is set to the mold. A continuous casting method of a slab in which the diameter is made 2 to 3 times the short side and then lightly reduced by a small diameter roll 5c near the crater end 9 (see Japanese Patent Laid-Open No. 1-178355).

At the position of the pass line of the crater end 9 of the cast slab 4, there is provided a reduction zone composed of a group of light reduction rolls 5c, and a guide having a roll interval widened by 5.0 to 0.5% with respect to the reference roll interval in front of this reduction zone. A bloom continuous casting method in which bulging forming blocks made up of roll groups 3b are continuously provided, bulging is formed on a slab, and then light reduction of 4.0 to 0.5% is performed (see Japanese Patent Laid-Open No. 2-235558).

Bulging is caused at a position where the solid fraction at the center of the slab 4 is 0.1 or less, the maximum thickness of the slab is made 20 to 100 mm thicker than the short side length of the mold 3, and the solidification completion point 9 Just before 1
A continuous casting method in which a reduction of 20 mm or more is applied to a pair of reduction rolls 5c to reduce the amount corresponding to the bulging amount (JP-A-9-57410).
(See Japanese Patent Publication).

During the solidification of the slab 4 until the unsolidified thickness is 30 mm or more, bulging is caused in the slab, and the maximum thickness of the slab is increased by 10 to 50% of the short side length of the mold 3 to solidify. A continuous casting method in which at least one pair of reduction rolls is used to give a reduction with a reduction gradient of 80 mm / m or more per slab length until just before the completion, and to reduce the amount corresponding to the bulging amount (see JP-A-9-206903).

The interval between the guide rolls 3b arranged in the slab withdrawing direction between the liquid layer line crater end 9a of the slab 4 and the end of the bulging zone is gradually increased to form a slab. Continuous casting method to prevent central segregation and internal cracking by causing bulging in the bulging zone and applying a reduction between the end of the bulging zone and the solidification completion point 9 (JP-A-9-3142).
(See Japanese Patent Publication No. 98).

[0017]

The "bulging-reduction method" proposed above defines operating conditions during steady casting. However, "bulging-
In the “rolling down method”, a special phenomenon occurs in the early stage of casting and the final stage of casting. The "initial stage of casting" is a period after the start of casting until the "bulging-reduction method" can be carried out within a predetermined range. The "end of casting" is the period after stopping the injection of molten steel into the mold. Both are called unsteady casting times.

For example, when bulging is caused in the early stage of casting, the molten metal level in the mold fluctuates up and down. To prevent this, the interval between the guide rolls is widened to cause bulging at a specific time when the casting speed becomes steady. Also,
If the casting speed is reduced at the end of casting, steel leakage may occur. In order to prevent this, it is necessary to make the bulging volume larger than that during steady casting to prevent the molten steel from leaking from the bottom portion without changing the drawing speed of the slab.

Usually, in the continuous casting method, since the molten steel is not supplied at the final stage of casting, it is necessary to perform a special treatment different from that in steady casting.

FIG. 2 is a diagram showing an example of a pattern for changing a casting speed (drawing speed of a slab) at the time of finishing the casting.
As shown in the figure, in the pouring end process, a deceleration pattern prepared in advance is used, and the casting speed is decelerated according to the residual molten steel weight and the residual molten steel level in the tundish at the final stage of casting. When the casting is completed, a so-called bottom treatment is performed in which a cooling material (metal particles, metal pieces, water, etc.) is poured into the last end portion (bottom portion) of the molten steel in the mold to be solidified. After that, the drawing speed (casting speed) is increased and the slab is drawn from the pinch roll. The above process is called "deceleration / bottom process at the final stage of casting" and is disclosed in, for example, Japanese Patent Publication No. 3-54025.

The inventors have found that when such "deceleration / bottom treatment" is applied at the final stage of casting of the "bulging-reduction method", for example, the following problems occur.

(1) By lowering the casting speed, the amount of heat removed from the slab per unit time increases, and the liquid phase line crater end and solid phase line crater end move to the mold side.
For this reason, the position where bulging or reduction falls outside the proper range, internal cracking or center segregation occurs in the slab, and the quality deteriorates.

(2) When the solid-phase crater end moves to the mold side, the pressing roll presses down the completely solidified portion, which may damage the roll equipment.

(3) If the "bulging-reduction" is continued under the same conditions as the steady casting after the bottom treatment, unsolidified molten steel squeezed by the reduction leaks from the bottom part, which may cause damage to equipment and risk to operators. Invite.

(4) If the reduction is stopped at the end of casting, the problems (2) and (3) can be solved. However, center segregation remains in the slab and the cross section has a bulging shape, which adversely affects processes such as rolling.

In order to solve such a problem, the roll speed of the guide roll group and the reduction roll group is narrowed as the casting speed is reduced at the final stage of casting, the bulging amount and the reduction amount are made smaller than those in the steady casting, and It is advisable to move the reduction position to the mold side. For this purpose, the guide roll group or the reduction roll group needs to have a structure in which the roll interval can be freely changed.

An object of the present invention is to provide a guide roll device capable of freely changing the roll interval in such an unsteady state (the initial or final stage of casting).

[0028]

[Means for Solving the Problems] The inventors of the present invention worked on the development of a guide roll device capable of realizing the "bulging-roll-down method" even in steady and unsteady conditions, and incorporated individual guide rolls and a plurality of them. Confirm that this can be solved by moving the frame in the thickness direction of the slab,
The present invention has been completed.

The gist of the present invention resides in the guide roll device and the continuous casting method in the continuous casting shown in FIGS. 5 and 6.

A bulging-rolling down guide roll apparatus G for continuous casting equipment, wherein each guide roll 5
b is provided with a moving device 10 whose axis is horizontally opposed to the thickness direction of the slab 4 and is movable in the thickness direction of the slab, and further includes a plurality of guides on one side of each slab. The rolls are connected by a frame body 11, and opposing frame bodies 11-1, 11-2
Is the guide that faces the deceleration / bottom processing at the end of casting.
The bulge is adjusted by adjusting the interval of the drool compared to the steady casting.
And reduce the rolling amount and adjust the rolling position.
That is a device that are connected by four hydraulic device 12 (Fig. 5, reference).

The hydraulic device 12 for connecting the moving device 10 and the frames 11-1 and 11-2 provided on the guide roll 5b is provided with a position detecting device 18, and inputs a casting speed and a position detected value. It is connected to a control unit (for example, a simple servo valve 16) operated by a control device 20 that adjusts the movement amount of the moving device. Further, it is desirable that the above-mentioned guide roll group is continuously provided in the casting direction between a position corresponding to the liquidus crater end of the slab and a position corresponding to the solidus crater end.

Further, the continuous casting method by the bulging-reduction method using the continuous casting guide roll device G,
The guide roll device G is provided as a guide roll group in which the axis of the guide roll is horizontally opposed in the thickness direction of the slab and is opposed to each other, and the guide roll groups on one side of each of the slabs are connected by a frame body to face each other. The body is composed of four hydraulic devices connected to each other, the interval between the guide rolls is narrowed as the casting speed is decelerated at the end of casting, the amount of bulging and the amount of reduction are smaller than that during steady casting, and the position of reduction is set. It is a continuous casting method characterized by moving to the mold side. The above hydraulic device is provided with a position detection device, and a signal from a control device that determines the amount by which the guide roll should be moved in the thickness direction of the slab from the deceleration information and the position detection value of the casting speed at the end of casting. based on, adjust the spacing of opposing the guide roll. The control device described above is a device that takes in the output from the position detection device 18 and the casting speed and controls the servo amplifier 22 of the simple servo valve 16 by a control program (see FIG. 6).

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is a schematic cross-sectional view showing a casting state by the bulging-rolling down method, (a) shows a state at the time of steady casting, and (b) shows a state at the final stage of casting. .
Although a curved type continuous casting equipment is shown in this figure, a vertical type continuous casting apparatus may be used. The slab may be a slab, a bloom or a billet, but the device of the present invention is suitable for continuous casting of a slab which is a material such as a thick steel plate.

At the time of steady casting, as shown in FIG. 3 (a), in the bulging zone, the guide roll group 5a is widened in the direction of the short sides of the slabs to cause bulging of the slabs, and then the squeeze rolls 5c are used to Roll down with a rolling amount equivalent to or less than the bulging amount.

At the end of casting, the molten steel is no longer supplied as shown in FIG. 3 (b), so the above-mentioned "deceleration / bottom treatment" is carried out. That is, as the casting speed decreases, the guide roll group
The roll interval between 5b and the rolling roll group 5c is narrowed, the bulging amount and the rolling amount are made smaller than in the steady casting, and the rolling position is moved with the movement of the solidus line crater end 9 to the mold side. ing.

Specifically, as shown in FIG. 2, a temporal change pattern of the casting speed from the start of deceleration of the casting speed to the end of casting is determined in advance. The predicted casting amount from the start of deceleration to the end of casting is calculated according to this pattern. Then, when the measured value of the weight of the molten metal in the tundish reaches the calculated predicted casting amount, the speed reduction process of the casting speed is started according to the pattern.

The conditions of bulging and reduction when performing the deceleration / bottom treatment method at the final stage of casting will be described in more detail below.

FIG. 4 is a schematic cross-sectional view of a slab for explaining the conditions of bulging and reduction when performing the deceleration / bottom treatment method at the final stage of casting, and FIG. 4 (a) shows the situation during steady casting. Figure, (b) is a diagram showing the situation from the start of deceleration of casting speed to the middle of deceleration, (c) Drawing is stopped for bottom processing, after that, the speed is increased and the slab is withdrawn It is a figure which shows the situation of.

The method of the present invention for the final stage of casting in the bulging-reduction method will be described in more detail with reference to this drawing.

Operation during Steady Casting As shown in FIG. 4 (a), the slab 4 has a bulging zone in which, for example, the short side of the slab is 1.1 to 1.5 times the short side dimension of the mold.
After being doubled, the amount of reduction equal to or less than the amount of bulging is applied in the reduction zone. The amount of reduction is set to be a slab having a thickness substantially equal to the bulging amount and the same thickness as the short side of the mold, but a slab slightly thicker than the short side of the mold may be manufactured by making it smaller than the bulging amount.

[0041] an operation using the casting end of the first half of the cast end (generally the period indicated by A in FIG. 2), in from the time of starting the deceleration of the casting speed up to the middle of the deceleration, as shown in FIG. 4 (b), Val managing zone And the roll interval in the reduction zone is gradually narrowed as the casting speed decreases. The amount of bulging and the amount of reduction are made slightly smaller than those during steady casting. During this period, the movement of the solid-phase crater end 9 is within the reduction zone during steady casting, and the reduction position may be moved to the mold side.

In the latter half of the last stage of casting (generally indicated by B in FIG. 2), the operation casting speed is further reduced and stopped, and after bottom processing is performed, the speed is increased to withdraw the slab. During this period, as shown in FIG. 4 (c), the solidus crater end 9 moves to the bulging zone during steady casting. For this reason,
It is necessary to carry out reduction even in the bulging zone. The amount of bulging and the amount of reduction at this time are made smaller than those in the above case.

Position L _{SCE of the} above solidus crater end 9
Can be calculated as the length from the meniscus using the formula:

L _SCE = (t / K) ² × Vc / 4 where t is the thickness (m) of the slab, K is the solidification coefficient, and Vc is the casting speed (m / min).

By performing the above-mentioned treatment, it is possible to prevent steel leakage from the end of the slab and prevent center segregation up to the end of the slab, and to perform casting with good yield.

5A and 5B are views showing a guide roll device for continuous casting according to the present invention. FIG. 5A is a partial cross-sectional side view seen from the short side of the slab, and FIG. 5B is seen from the casting direction. FIG. 7A is a sectional view taken along line XX, and FIG. 7C is a sectional view taken along line YY of FIG. These figures show the guide roll device G at a position corresponding to the horizontal part of the curved continuous casting equipment.

This guide roll device G includes a guide roll 5
A moving device (10) is provided, which has its axis (b) horizontally opposed to the thickness direction of the slab (4) and is movable in the thickness direction of the slab (4). Further, a plurality of guide rolls provided on the slab side are connected by a frame 11. Its opposing frame 11
-1, 11-2 are connected at their four corners by four hydraulic devices 12. The device can either widen the roll spacing to bulge the slab, or narrow it for rolling down.

The guide rolls 5b are provided so as to face each other with the short side of the cast piece 4 sandwiched therebetween, and both ends thereof are supported by the axle box 13 and the pedestal 14. The moving device (10) slides in the pedestal (14) and can move in the short side direction of the slab. The moving device 10 may be any device that incorporates a hydraulic device or an eccentric shaft, that is, a device that can reciprocate linearly. This moving device causes bulging of the cast slab to perform the rolling or the rolling position.

In these guide roll devices G, a plurality of guide rolls 5b arranged on one side of the cast slab are used for the frame bodies 11-1 and 11
-2 is fixed via the moving device 10. Two frames 11
-1, 11-2 are connected at the four corners by four hydraulic devices 12 in the short side direction of the slab. The four hydraulic devices have a structure in which the space between the frame bodies is adjusted as shown by the broken line to widen or narrow the roll space between the inlet side and the outlet side of the slab.

This guide roll device is provided between the liquidus line crater end (see reference numeral 9a in FIG. 1) and the solidus line crater end (see reference numeral 9 in FIG. 1) of the slab during steady casting. Has been. The roll interval of the guide roll 5b is
It is desirable to be able to adjust up to 1.5 times the short side length of the mold.

FIG. 6 is a block diagram of a system for controlling the movement of the guide rolls.

The hydraulic device 12 for fastening the frames 11-1 and 11-2 is
Hydraulic valve stand via each simple servo valve 16
Piped up to 17. Further, a position detector 18 is built in or attached to the hydraulic device 12, and the position of the cylinder rod is input to the control device 20 via an AMP card (position detection converter) 19.

The simple servo valve 16 is a D / A conversion card (converter from digital to analog) 21 from the control device 20 which incorporates speed information of deceleration / bottom processing at the end of casting and position information from the position detector 18. And a signal is sent via a servo amplifier (signal amplifier) 22. As a result, the liquid amount of the hydraulic device 12 is adjusted, and the roll interval of the guide roll 5b is adjusted. The control device 20 used here is a computer,
It may be a personal computer directly connected to the vidicon. Also, a hydraulic servo system, a stepping cylinder control system or the like can be used.

Since the guide roll device of the present invention has the above structure, the roll interval of the guide rolls can be freely changed. Further, this device can move the rolling position with the movement of the solidus crater end of the cast slab. Thereby, the bulging-rolling-down method can be stably carried out even in the initial stage or the final stage of casting.

[0055]

EXAMPLE A casting test of aluminum-killed carbon steel was conducted by using the apparatus shown in FIGS. 5 and 6 in a curved type continuous casting apparatus.
The internal mold section of the mold used is 230 mm thick and 230 mm wide.
The casting condition is 0 mm, the casting speed is 1.0 m / min, the bulging amount during steady casting is 20% (46 mm), and the rolling reduction is 20% (46 mm) of the bulging equivalent amount, from the start of deceleration at the end of casting. The bulging amount and the reduction amount were changed as shown in Table 1. FIG. 2 is a diagram showing a deceleration pattern in the final stage of casting used in this test.

[0056]

[Table 1]

The evaluation of the invention was carried out based on the average amount of steel leakage generated from the bottom of the slab and the maximum value of the center segregation degree of the bottom of the slab.

The P maximum segregation degree was obtained by cutting the obtained slab at a position 3 m from the end of the slab in a cross section perpendicular to the casting direction, collecting a test piece from the center in the thickness direction, and measuring the surface of the test piece at 200 μm. It is divided into meshes, the P concentration is measured using EPMA in each division, and the ratio between the maximum P concentration [Pmax] and the P concentration [Pave] of the parent molten steel ([Pmax] / [Pav]
e]). The results of these investigations are also shown in Table 1.

From Test No. 1 to Test No. 6 of the invention examples, the casting speed was decreased at the end of casting, and at the same time, the bulging amount and reduction amount were 20% at the time of steady casting, and as shown in Table 1, 0.5 to 7.0. % To complete casting. In these invention examples, only a slight leakage of steel was observed in Test No. 6, which had no effect on the operation, and the occurrence of leakage of steel was not observed in the other tests, and the P maximum segregation degree was also small. However, Test No. 5 is the amount of bulging and rolling at the end of casting.
Since it was reduced to 0.5%, the P maximum segregation degree was 5.25, which was slightly large.

Test No. 7 is a comparative example in which bulging and rolling reduction during steady casting were continued even at the final stage of casting.
In this example, the amount of bulging at the end of casting was as large as 20%, so there was 0.05 ton of leakage steel. Also, due to the movement of the solidus crater end, the position of bulging and rolling down became improper, so complete rolling down was not possible (bulging amount was 20% and rolling amount was 10%), and the center segregation degree was as large as 6.8. It was

Test No. 8 is an example of a normal continuous casting method in which neither bulging nor reduction is performed, and the P maximum segregation degree is 13.3.
And very big.

[0062]

[Effect of the Invention] The present invention guide roll apparatus and this
According to the continuous casting method used, proper bulging and reduction can be continued even in the initial stage or the final stage of casting. As a result, the center segregation of the slab at the final stage of casting is also reduced, the amount of material discarded as poor quality is reduced, and the casting yield is greatly improved. Further, this device can be used even during unsteady operations such as operation troubles, quality troubles, equipment troubles and the like that occur during operation.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an example of a continuous casting method for explaining the principle of the bulging-rolling-down method.

FIG. 2 is a diagram showing an example of a pattern of changing a casting speed (drawing speed of a slab) at the time of a casting end process.

FIG. 3 is a schematic cross-sectional view showing a casting situation by the bulging-reduction method, (a) showing a situation during steady casting and (b) showing a situation at the final stage of casting.

FIG. 4 is a schematic cross-sectional view of a slab for explaining the conditions of bulging and reduction when performing the deceleration / bottom treatment method at the final stage of casting, and (a) is a diagram showing the situation during steady casting, (b) is a diagram showing the situation from the start of deceleration of the casting speed to the middle of the deceleration, (c) is the situation during the period when the withdrawal is stopped for bottom processing and then the speed is increased to withdraw the ingot. FIG.

FIG. 5 is a diagram showing a continuous casting guide roll device of the present invention, in which (a) is a partial cross-sectional side view seen from the short side of the slab,
(b) is a cross-sectional view taken along the line XX in (a) as viewed from the casting direction, and (c) is
It is a YY sectional view of (a).

FIG. 6 is a block diagram of a system for controlling the movement of a guide roll.

[Explanation of symbols]

1. Molten steel 2. Immersion nozzle 3. Template 4. Slab
4a. Solidification shell 4b. Uncoagulated part 5. Guide roll 6. Pinch roll 7. Electromagnetic stirrer 8. Reduction device 9. Solid phase crater end 9a. Liquid phase crater end G. Guide roll device

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyuki Soejima 5-2 Sokai-cho, Niihama-shi, Ehime Sumitomo Heavy Industries, Ltd. Niihama Factory (72) Inventor Masa Umeda 5-2 Sokai-cho, Niihama-shi, Ehime Sumitomo Heavy Industries, Ltd. Niihama Works (56) References JP-A-9-99348 (JP, A) JP-A-5-15956 (JP, A) JP-A-6-182515 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B22D 11/128 350 B22D 11/128 310 B22D 11/20 B22D 11/16

Claims (6)

(57) [Claims] 1. A guide roll device of a continuous casting facility for bulging a cast slab and then reducing the slab, wherein the respective guide rolls are provided with their axes horizontally facing each other in the thickness direction of the cast slab. Equipped with a moving device that can move in the thickness direction of
Furthermore, the guide rolls on each side of the slab are connected by a frame body, and the opposing frame bodies are decelerated / bottomed at the end of casting.
Adjust the distance between the guide rolls facing each other at
Smaller bulging amount and reduction amount than when casting
The continuous casting guide roll device is characterized by being connected by four hydraulic devices for adjusting the rolling position. 2. A hydraulic device for connecting a moving device provided on the guide roll and a frame body with a position detecting device, and a control for adjusting a moving amount of the moving device by inputting a casting speed and a position detection value. The continuous casting guide roll device according to claim 1, wherein the continuous casting guide roll device is connected to a control unit operated by the device. 3. The guide roll group is continuously provided in a casting direction between a position corresponding to a liquidus line crater end of a slab and a position corresponding to a solidus line crater end. The continuous casting guide roll device according to claim 1 or 2. 4. A continuous casting method in which a slab is bulged by using a continuous casting guide roll device and then rolled down, wherein the guide roll device horizontally opposes the axis of the guide roll in the thickness direction of the slab. Provided as a group of opposing guide rolls,
The guide rolls on one side of each of the slabs are connected by a frame body, and the opposing frame bodies are connected by four hydraulic devices,
A continuous casting method characterized by narrowing the interval between the guide rolls facing each other as the casting speed decreases in the final stage of casting, making the bulging amount and the rolling reduction smaller than at the time of steady casting, and moving the rolling position to the mold side. . 5. The hydraulic device is provided with a position detecting device, and determines the amount by which the guide roll should be moved in the thickness direction of the slab from the deceleration information of the casting speed at the final stage of casting and the position detection value. The continuous casting method according to claim 4, wherein the interval between the guide rolls facing each other is adjusted based on a signal from a control device. 6. The guide rolls, which are opposed to each other, are provided continuously in the casting direction between the position corresponding to the liquidus line crater end of the slab and the position corresponding to the solidus line crater end. 6. The continuous casting method according to claim 4 or 5, wherein the interval is adjusted.