JPH0328991Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a mold roll in continuous thin plate casting equipment.

BACKGROUND OF THE INVENTION Some continuous thin plate casting equipment uses twin roll molds. This thing consists of a pair of rolls 21, 21 as shown in FIG.
and a pair of long side weirs 22a, 22a and a pair of short side weirs 22 arranged on these rolls 21, 21.
It is composed of a molten steel receiver 22 consisting of b, 22b,
Molten steel 23 placed in a molten steel receiver 22 is drawn out as a slab 24 by a pair of rolls 21, 21, and a thin plate is cast. By the way, according to the above configuration, as shown in FIG. 11, the wall shell 25 that grows on the wall surface of the short side weir 22b near the corner of the long side weir 22a and the short side weir 22b is a part of the newly formed cast iron. It is solidified and bonded to the piece shell 26, and the cast piece shell 26 is
As the bond is moving, the bond breaks, and this bond and break are repeated, eventually resulting in a breakout. In particular, as shown in FIG. 12, in the short side weir 22b, the wall shell 25 of the short side weir 22b comes to cover the newly generated slab shell 26 from above, and the gap between both shells 25, 26. 27 molten steel rapidly solidifies and adheres to each other. However, since the slab shell 26 is moving, it pulls against the wall shell 25, and the thinnest and weakest part of the shell breaks, which causes the wall shell 25 to break.
It remains on the 5 side and grows large to form slab shell 2.
It restricts the movement of 6 and develops into a breakout.
Further, in the middle of the slab shell 26, the slab shell 26 comes into contact with the roll 21 and its thickness increases, and the state of contact with the roll 21 changes periodically. For this reason, uneven generation occurs in the slab shell 26. For example, when a large slab shell 26 moves, the gap disappears, solidifies and adheres to the wall shell 25, and the moving slab shell 26
A tensile force is generated between the 6 and 6, which develops into a breakout. By the way, as a solution to the above-mentioned problems, a configuration disclosed in Japanese Utility Model Application Publication No. 153047/1983 has already been provided. This has a protrusion formed at the lower end of the short side weir located between a pair of rolls. According to this configuration, as shown in FIG. 13, the protrusion 31 sufficiently absorbs heat from the molten steel and becomes hotter than the other wall surfaces 32. Therefore, the thickness of the slab shell 33 becomes thinner, and therefore the protrusion 31
The wall shell (restriction shell) that is generated in this process is high temperature and weak in strength. Moreover, the contact portion between the wall shell 34 and the slab shell 33 that is generated on the other wall surface 32 is eliminated.

Problems that the invention attempts to solve By the way, even with the above configuration, there is still the problem of breakouts occurring. That is, as shown in FIG. 14, in the generation gap of the slab shell 33, the slab shell 33 is thin and the wall shell 3
4 grows close to the surface 35 of the roll 21. Note that when the height of the protrusion 31 is reduced, a wall shell that restrains the slab shell grows without reaching a high temperature due to the cooling effect of the roll 35.

Therefore, an object of the present invention is to provide a mold roll for continuous thin plate casting equipment that can solve the above problems.

Means for Solving the Problem In order to solve the above problem, the mold roll in the thin plate continuous casting equipment of the present invention has a molten steel receiver made up of a pair of short side weirs parallel to each other and a pair of long side weirs, A twin-roll type mold having a pair of rolls parallel to the long side weir is placed below the molten steel receiver, and the molten steel in the molten steel receiver is continuously drawn out between the rolls to continuously cast a thin plate. In the mold rolls in the equipment, metal rings are attached to the outer peripheral surface of each roll at positions corresponding to both short side weirs, and the surfaces of these metal rings that face each other in the roll axis direction and the inner peripheral surface A refractory ring is provided at the corner formed by.

Effect According to the present invention having the above configuration, when a slab is being pulled out from the molten steel receiver by a pair of rolls, the metal ring is provided in contact with the outer peripheral surface of the rolls, so that the metal ring is successively drawn from the molten steel from the contact surface. The parts in contact with each other will be cooled down, and therefore the slab shell formed on the roll surface will grow to a large extent on the opposing surface of the metal ring, gaining strength. Furthermore, as the temperature of the wall increases, the wall shell becomes thinner and weaker. Due to these synergistic effects, the slab shell is no longer constrained by the wall shell, and breakout of the slab shell can be prevented. Furthermore, the refractory ring increases the frictional force with the shell due to the refractory surface, providing a synchronizing force.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 8. In Figures 1 to 3, 1 is a box-shaped molten steel receiver, and a pair of short side weirs 1 parallel to each other.
a, 1a, and a pair of long side weirs 1b, 1b. This molten steel receiver 1 is usually made of a refractory material with high heat insulation properties. Reference numeral 2 denotes a twin roll mold, which is placed below the molten steel receiver 1. This twin roll type mold 2 consists of a pair of rolls 3, 3 parallel to the long side weirs 1b, 1b, and the outer peripheral surfaces of these rolls 3, 3 are used to form both short side weirs 1.
Metal rings 4, 4 made of stainless steel, copper, etc. and having a predetermined thickness a are attached to positions corresponding to a and 1a. Then, annular recesses 5, 5 are formed in the corner portions of the metal ring formed by opposing surfaces in the roll axis direction and the inner circumferential surface, and these recesses 5,
Rings 6, 6 made of a refractory material with good heat conductivity are fitted inside the ring 5, and are fixed with a ceramic adhesive. Therefore, when the rolls 3, 3 rotate, both rings 4, 4, 6, 6 also rotate at the same rotational speed. The width of the metal rings 4, 4 is as shown in FIG.
It may be made wider than the width of the weir 1a, or it may be made substantially the same as the width of the short side weirs 1a, 1a, as shown in FIG. And the short side weirs 1a, 1a in the sliding part
Recessed spaces 7, 7 are provided on the bottom surface of the metal ring 4, so that the contact area is minimized so that the heat from the molten steel receiver 1 does not transfer to the metal rings 4, 4. Furthermore, as shown in FIG. 4, rings 4, 4, 6,
A large number of grooves 8, 8 along a cycloidal curve are formed on the inner side surface (molten steel side side surface) of 6. Note that instead of the grooves 8, 8, a large number of uneven portions may be formed.

Therefore, in a state where the rolls 3, 3 are rotating in the direction of arrow A, both rings 4, 4, 6, 6
enters into the molten steel 9 from the long side weirs 1b, 1b together with the rolls 3, 3. At this time, the thin slab shell 1 comes into contact with the molten steel 9 for the first time, as shown in Figure 3.
0 is generated. At that time, the metal rings 4, 4 are
Since it is fixed in contact with the outer circumferential surfaces of the rolls 3, 3, it is cooled by the rolls 3, 3 through the contact surface, and further, from the contact surface, the parts that come into contact with the molten steel 9 are sequentially cooled. Therefore, the slab shell 10 generated on the roll surface is largely generated on the inner circumferential surface of the metal rings 4, 4, and has strength. Further, the short side weirs 1a, 1a are made of refractory material, and the walls 11 are heated to a high temperature due to the spaces 7, 7 for minimizing the area of contact with the metal rings 4, 4. is thin and weak. Due to these synergistic effects, the short side weir 1a,
Even if the wall shell 11 generated at 1a grows to capture this thin slab shell 10, it will not reach the long side 10a of the slab shell 10 due to the thickness of the metal rings 4, 4, and the wall will not reach the long side 10a of the slab shell 10. The shell 11 breaks at the rotating metal rings 4, 4. Moreover, even if the wall shell 11 is the slab shell 10
Even if an attempt is made to bond the slab shell 10 to the groove 8,
8, the slab shell 10 is firmly held by the metal rings 4, 4, so that the slab shell 10 is separated from the wall shell 11. In addition, short side weirs 1a, 1a
The spaces 7, 7 on the lower surface prevent the heat on the molten steel receiver 1 side from escaping to the rolls 3, 3 side.
The growth of wall shell 11 is suppressed. and,
As the slab 12 moves, the slab shell 10 gains strength due to cooling from the rolls 3, 3, and is no longer captured by the wall shell 11. By the way, if the long side portion 10a of the slab shell 10 has strength, the risk of breakout will be reduced, but the slab shell 10 will deform away from the rolls 3, 3. That is, as shown in FIG. 5, when the slab shell 10 shrinks on the cylindrical surface, the temperature distribution in the thickness direction of the shell always causes the slab shell 10 to fall on the rolls 3, 3, which is caused by uneven production of the shell. The deformation occurs even if the radius is smaller than the arc of the circle, and at this time, voids 13 are created and shell formation is delayed. If these promote shell unevenness and become as shown in Fig. 6, the newly formed slab shell 10 will become buoyant.
It is not remelted by new molten steel 9 to form a continuous slab shell, but also continues to break out. Regarding this floating, the metal rings 4, 4 are also effective and play a role of suppressing floating of the slab shell 10. Furthermore, in the case of twin rolls as described above, as shown in FIG. In the case of alloy steel, if the comrades interfere and solidify into a slab,
In particular, negatively segregated materials occur inside the slab, deteriorating product quality. To avoid this, the inside must be unsolidified between the rolls. Further, at this time, the thickness of the short side portion 10b of the slab shell 10 needs to be equal to or larger than the inter-roll gap dimension in total of the left and right shells. Therefore, in order to form a shell having such a shape, the thickness of the short side 10b of the shell must be greater than the thickness of the long side 10a of the shell. 4,4
This protects the short side portion 10b from the wall shell 11 and allows it to grow actively.

As shown in Figure 8, both weirs 1a, 1a, 1b,
At the corner with 1b, the molten steel 9 cools and begins to solidify, which is the line E-F-G. The shell grows as it moves from this E-F-G line in the casting direction B. E of long side weir 1b, 1b
- Since a wall shell is generated in the part corresponding to F-G, the initial thin shell generated at E-F of the short side weirs 1a and 1a solidifies and adheres to the wall shell, and the shell is damaged as much as possible to form the slab shell 10. Sometimes it happens. In order to prevent this, in particular, in order to give synchronizing force to the short piece shell between F and Fa, the refractory surface is made using refractory rings 6, 6, and a very thin shell is generated to increase the frictional force with the shell. I'm trying to make it happen. Furthermore, if a cooling type metal ring is used between F and Fa, the long side weirs 1b and 1b
The refractory at corner F of the LEFG will be cooled excessively compared to the other parts, and a wall shell will easily form, causing trouble, but the refractory rings 6, 6 have the role of preventing this. be.

Note that the cycloidal grooves 8, 8 formed in the surface where the shell is generated in the initial shell portion effectively provide synchronization and allow the slab 12 to come out without any problem at the mold exit.

FIG. 9 shows another embodiment. That is, a water-cooled type is used in which a cooling water chamber 14 is formed on the inner peripheral surface of the metal rings 4, 4. In this case, the width of the metal rings 4, 4 is adjusted to suit the width of the cast slab. can be changed. At that time, the short side weir 1a of the molten steel receiver 1,
The width of 1a is also changed. Reference numeral 15 indicates the roll axis, and arrows indicate the flow of cooling water.

Effects of the invention According to the structure of the invention described above, the metal ring provided in contact with the outer periphery of the roll at a position corresponding to the wall of the molten steel receiver is cooled sequentially from the contact surface to the part in contact with the molten steel. Over time, the slab shell formed on the roll surface grows to a large extent on the opposing surfaces of the metal ring, gaining strength.
Furthermore, as the temperature of the wall increases, the wall shell becomes thinner and weaker. Due to these synergistic effects, the slab shell is no longer constrained by the wall shell, and breakout of the slab shell can be prevented. Furthermore, the refractory ring can increase the frictional force with the shell due to the refractory surface, and can provide a synchronizing force.

[Brief explanation of drawings]

Figures 1 to 8 show an embodiment of the present invention, in which Figure 1 is a perspective view of the mold, Figure 2 is an overall sectional view, Figure 3 is a sectional view of the main part, and Figure 4 is a ring. 5 to 7 are sectional views explaining the action,
FIG. 8 is an explanatory diagram of shell generation, FIG. 9 is a sectional view showing another embodiment, FIGS. 10 to 14 are conventional examples, FIG. 10 is an overall sectional view, and FIG. A perspective view of the main part, and FIGS. 12 to 14 are sectional views of the main part. 1... Molten steel receiver, 1a, 1a... Short side weir, 1b,
1b... Long side weir, 2... Twin roll mold, 3, 3... Roll, 4, 4... Metal ring, 5, 5... Recess, 6, 6... Refractory ring, 7, 7... Space, 8, 8... Groove, 9... Molten steel, 10... Slab shell, 11... Wall shell, 1
2... Slab, 14... Cooling water chamber.

Claims (1)

[Scope of utility model registration request] A molten steel receiver is constituted by a pair of short side weirs parallel to each other and a pair of long side weirs, and a twin roll type mold having a pair of rolls parallel to the long side weir is arranged below the molten steel receiver. , a mold roll used in continuous thin plate casting equipment for continuously casting thin plates by continuously drawing out the molten steel in the molten steel receiver from between the rolls, and each roll has a metal mold roll at a position corresponding to both short side weirs on the outer peripheral surface of each roll. 1. A mold roll for use in continuous thin plate casting equipment, characterized in that a ring is attached and a refractory ring is provided at a corner portion formed by an inner circumferential surface and a surface of these metal rings that face each other in the direction of the roll axis.