JPS6021164A - Method and device for continuous casting of thin plate - Google Patents

Abstract

PURPOSE:To obtain continuously a thin billet having a good surface characteristic directly from a molten metal by changing the casting direction to a horizontal direction and forming one surface of a casting mold as a molding board surface and the opposed surfaces as moving surfaces by rolls. CONSTITUTION:A molding board 1 consists of a start side molding board 1s formed of refractories and a table-side molding board 1r which contains a water-cooling mechanism and of which the top surface is formed of refractories. Both boards are placed horizontally at a prescribed width, the latter behind the former, thus forming one surface of the casting surface which extends horizontally. A roll group 2 orthogonal to the advancing direction of a billet is rotatably provided above the board 1 apart at the space necessary for the thickness of the billet to be cast from the top surface of said board 1, thereby forming the opposed casting surfaces. The group 2 consists of start side rolls 2s of which the surface is formed of refractories and table roll 2r which contain a water-cooling mechanism and of which the surface is a metallic plate. Both rolls have the horizontal shafts parallel with each other apart at a prescribed space from each other. A perpendicular stationary wall 3 for regulating the width of the billet is provided and the molten metal is poured continuously from the discharge port 6 of a holding vessel 4, by which a thin billet 5 is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous thin plate casting method and a casting machine for manufacturing a wide thin plate slab from molten metal, particularly molten steel, by continuous casting with good operability by moving one side of a mold in synchronization with the slab.

In the continuous casting of steel, thick slabs have traditionally been continuously cast, and conventional continuous casting machines have difficulty controlling the thickness from various aspects such as product shape, internal quality, solidification adjustment, and molten metal supply9. It was difficult to produce the lower sheet slab. In recent years, twin rolls or twin belts have been developed, as seen in, for example, JP-A-55-75862, JP-A-57-9566, JP-A-58-32548, and JP-A-58-32551. Proposals have been made to produce thin plate slabs (steel plate slabs) with a thickness of 10 mm or less directly from molten metal using surface moving molds such as the above, but there are still many problems that need to be solved and there are still practical problems. So far, nothing has been established.

For example, in the twin roll method, it is difficult to adjust the solidification because the contact distance with the molten metal is not sufficient, and the slab is likely to break due to insufficient cooling. A typical problem is that the roll diameter inevitably becomes large. On the other hand, the typical problem with the twin belt method is that the rolling capacity is small, and therefore it is difficult to obtain slabs with a smooth surface, which tends to result in uneven shapes.

The purpose of the present invention is to fundamentally solve the problems of the twin-roll method and the twin-held method.
This invention has devised a method and apparatus for casting a wide thin slab by changing the stitching direction to the lateral direction and capable of stable casting, also called the single-sided moving surface method. That is, in the present invention, molten metal is continuously cast into a plate shape having a predetermined width on a horizontally extending surface plate, and while moving on this surface plate, This surface plate provides a direct thin plate continuous casting method from molten metal, which involves casting to the desired thickness using rolls that can be rotated and placed above the surface plate with a predetermined gap. . And, as a device for carrying out this method, 1
As shown in the drawing, a fixed mold surface consisting of a surface plate 1 extending horizontally with a predetermined width, and a gap corresponding to the thickness of the slab placed above this surface plate 1 so as to be rotatable. A mold for thin plate slabs is formed by a movable mold surface consisting of rolls 2 with horizontal axes and vertical fixed walls 3 on both sides that regulate the width of the slab, and a molten metal holding container 4 is attached to this mold. To provide a thin plate continuous casting machine in which molten metal is continuously injected.

The present invention will be specifically described below with reference to one drawing.

As shown in FIG. 1, the surface plate 1 includes a start measurement board 1s whose at least the upper surface is made of refractory material, and a water cooling mechanism inside and whose upper surface is made of a metal plate (for example, a copper plate or a steel plate). It consists of a table measuring board 1r. Both are placed horizontally so that the former follows the latter with a predetermined width, but the former is located in a region that directly contacts the molten metal, and the latter is located in a region that forms a solidified shell or is in contact with the solidified shell. The upper surface of this horizontally extending surface plate 1 is.

In the present invention, one surface of the casting surface for casting the thin plate slab 5 is formed.

The casting surface that faces the horizontally extending fixed casting surface formed by the upper surface of the surface plate 1 is formed by a moving surface that moves in synchronization with the slab 5. More specifically, constant f! ? t1
The upper surface is the surface where a group of rolls, which are rotatably installed above the surface plate 1 in a direction perpendicular to the direction of progress of the slab with a gap necessary for the thickness of the slab to be cast, meet this synchronously moving surface. It has become. That is, the rotating surface of this roll forms a movable casting surface opposite to the fixed casting surface of the surface plate 1. This group of roles.

A start-side roll 2s, at least the surface of which is made of refractory material, and a table-side roll 2r, which has an internal water-cooling mechanism and whose surface is made of a metal plate (for example, a copper plate or a steel plate).
It consists of Both have horizontal axes, and the axes are parallel to each other, and they are placed above the surface plate 1 with a predetermined gap between them, and the start side roll 2s is in contact with the molten metal. The table-side rolls 2r are located at a portion forming or in contact with a coagulated shell, and are connected to each other without much spacing.

In addition to the fixed casting surface of the surface plate 1 and the movable casting surface by the rolls 2, a fixed wall 3a for regulating the width of the thin plate slab,
3b (FIG. 2) is provided vertically between the start measurement board 1s and the start side roll 2S.

FIG. 2 is thus formed. 7B? Continuously supplies molten metal to a laterally extending mold consisting of a fixed casting surface of surface plate 1, a movable casting surface by rolls 2, and fixed walls 3a and 3b? ! An example of the A holding container 4 is schematically shown. As shown in FIG. 2, the molten metal holding container 4 is a refractory container with an open top surface and a discharge port 6 provided below the front wall 7, and the molten metal flows from the discharge port 6 onto the start measurement board 1s. Installed so that it can be cast. Both side walls of this discharge port 6 are connected to fixed walls 3a, 3b, and these fixed walls 3a,
The molten metal flows out from the discharge port 6 onto the start measurement M1s which is dammed at 3b. On the other hand, on the fixed walls 3a and 3b near the discharge port 6, a start-side roll 2S having a width larger than the width between the fixed walls 3a and 3b is installed so as to be able to rotate nine times. As mentioned above, the start side roll 2s and the start measurement board 1s, which are in direct contact with the molten metal, are preferably made of refractory material. The molten metal flowing out from the discharge port 6 is released when the molten metal level in the molten metal holding container 4 is maintained at a predetermined level (when an amount of molten metal corresponding to the amount flowing out from the discharge port 6 is continuously supplied into the molten metal holding container 4). ), it will be extruded into this mold with a constant static pressure, and it will be given energy to move on the surface plate 1. Although this energy will vary depending on the inclination of the platen 1, sufficient energy is added by the moving mold surface by the rolls to move against the friction between the solidified shell and the mold.

Casting is carried out under conditions such that while the molten metal moves into a mold (preferably made of refractory material) surrounded by the start measurement 11s, the start side roll 2s, and the fixed walls 3a, 3b, it is slowly cooled and the formation of a solidified shell begins. However, if a solidified shell forms quickly on the fixed walls 3a, 3b side, the shape of the slab may become unstable, so it is necessary to prevent overcooling on both sides of the discharge port 6 and on the fixed walls 3a, 3b. heating means 8 for
(for example, an electric resistance thermal heater). After leaving the area surrounded by the start measurement board IS, the start roll 2S, and the fixed walls 3a and 3b, the table measurement board 1r and table roll 2r (
(all have internal cooling mechanisms), where they are forcibly cooled and further solidified to form slabs of the desired thickness. Completely solidified thin plate slabs can be pulled out from the 1& direction with a tensile force, but it is also possible to continue rolling them with rolls for the purpose of light reduction.

FIG. 3 shows an example in which, in addition to the start-side roll 2s, a table-side roll 2r (cooling roll) is also arranged on the fixed walls 3a, 3b.

Note that the start side roll 2s, which is the part that comes into direct contact with the molten metal, may not necessarily need to be rotated, and may be rotated as necessary. If there is a risk of metal leakage between the start-side roll 2s that contacts the molten metal and a fixed member (for example, the gap between this roll and the fixed walls 3a and 3b or the gap between the discharge port 6), It is recommended to apply an inert gas seal, etc.

In this way, according to the present invention, the contact distance with the mold can be extended freely, and the appropriate pressure necessary to maintain good surface quality can also be freely applied to the slab. Direct thin plate continuous casting from molten metal, especially molten steel, is provided, which eliminates the drawbacks of the proposed twin roll and twin heald methods.

[Brief explanation of drawings]

Figure 1 is an overall perspective view of the continuous thin plate casting machine of the present invention, Figure 2 is
The figure is a perspective view showing a part of the mold part. FIG. 3 is a schematic vertical sectional view showing another example of the casting machine of the present invention. 1... Constant fi, Is... Start measurement board, lr... Table measurement board, 2s... Start side roll. 2r...Table side roll, 3a, 3b...Fixed wall. 4. Molten metal holding container, 5. Thin plate slab.

Claims (2)

[Claims] (1) The molten metal is continuously poured into a plate shape with a predetermined width on a horizontally extending surface plate, and while moving on this surface plate, this surface plate and this surface plate are poured. This is a direct thin plate continuous casting method from molten metal, which involves casting to the desired thickness using rolls that are rotatably placed on a surface plate with a predetermined gap. (2) A fixed mold surface consisting of a surface plate 1 extending horizontally with a predetermined width, and a roll 2 rotatably disposed above this surface plate 1 with a gap corresponding to the thickness of the slab. This thin plate continuous casting machine has a movable mold surface consisting of a movable mold surface and a vertical fixed wall 3 regulating the width of the slab to form a mold, and molten metal is continuously poured into the mold from a molten metal holding container 4.