JPS58179545A - Continuous casting device of hoop - Google Patents

Abstract

PURPOSE:To provide a titled casting device which casts a steel hoop directly from molten steel, can improve production efficiency considerably and lessen the manpower and energy of a production line by the constitution wherein the molten steel is cast in an S shape into the clearance between two pieces of cooling rolls differing in peripheral speed. CONSTITUTION:A cooling roll 1 of upper stream side is rotated at a high speed and a cooling roll 2 of downstream side at a low speed. The molten steel 7 flowing in a molten steel flow passage 4 is cooled with the peripheral surface of the roll 1 to form a solidified layer 8. The layer 8 thereof is grown while it is moved to the side of the clearance between both rolls according to the rotation of the roll 1, and said layer is brought into contact with the roll 2 and is adhered with the solidified layer 12 formed similarly in the clearance part and the adhered layer is cast as a steel plate 3. The moving speeds of both layers 8, 12 give shearing deformation between both layers when the layer 8 adheres tightly to the layer 12 on account of a difference in the peripheral speeds of the rolls 1 and 2, thereby stirring the inside of the plate 3 and preventing the central segregation of non-metal. The molten metal is replenished into the part shrunk in the stage of solidifying by the shearing deformation given in said clearance, whereby the generation of cavity is prevented, the internal texture is fined on account of the shearing deformation and mechanical properties are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous strip casting apparatus that can significantly improve production efficiency, save labor on a production line, and promote energy savings.

The most common method for producing steel sheets, and one that is still in use today, is to cast thick slabs using a continuous slab casting machine and process them on a separate rolling line at 5 to 10 liters.
This is a method of manufacturing a plate by rolling it several times to make it thin, and then going through a finish rolling process in which a large number of finish rolling mills are arranged in tandem. However, this method requires heating the slab and controlling the temperature to a constant temperature for rolling, which requires a large amount of rolling energy as well as heating energy.

In addition, since the slab casting speed in the casting line and the rolling speed in the rolling line are different, it is impossible to run both lines continuously, and in order to manufacture strips, two lines are required. We have no choice but to install equipment. Therefore, the equipment becomes large-scale and equipment for connecting both lines is also required.

The present invention has been developed in view of the above circumstances, and a molten steel flow path is formed so as to wrap around the outer periphery of one of two cooling rolls arranged in parallel with an appropriate gap between them. The steel plate spun from the gap is further wound around the other cooling roll. By making the flow of the steel plate from the molten steel into an S-shape and by making the peripheral speed of both cooling rolls true, high-speed casting is possible. Speed can be matched with rolling speed. The present invention aims to improve the quality of cast steel sheets and to make it possible to manufacture high-quality thin steel sheets with fewer rolling cycles.

Embodiments of the present invention will be described below with reference to the drawings.

A cooling roll whose inner surface can be cooled with water, etc.
11 (2) are arranged in parallel with a gap corresponding to the thickness of the steel plate (3) to be cast, and both cooling rolls (+1
(21 can be rotated in the direction of the arrow in the figure so that the circumferential speed is true.One cooling roll +1) The molten steel flow path (4) is formed in the form of
Make sure to lead it to the gap of 2+. Hot water supply port (5) and molten steel flow path (
The supply path (6) that connects the supply path (6) with the molten steel flow path (1) has a fan shape that gradually becomes wider toward the molten steel flow path (1).
6), the flow velocity distribution and pressure distribution of the molten steel (7) are adjusted. Furthermore, the walls of each of the molten steel flow paths, the supply path (6) and the molten steel flow path (4), are designed to have a structure that is heat resistant and does not form a solidified layer. For example, there is a structure in which a heating device is built into a graphite insulated counter-flow passage surface, or a high alumina-based refractory material reinforced with iron skin on the counter-flow passage surface. Next, both the rolls (]) (
On the exit side of the gap 21, there is a foot guide (9) that peels off the coagulated layer (8) that has grown on the surface of the cooling roll (1) from the cooling roll (11), bends it, and presses it onto the cooling roll (2).
) will be established. Furthermore, a foot guide 00) is provided so that a corner is required for winding the steel plate (3) around the cooling roll (2), and guide rolls 0υ are appropriately arranged to guide the steel plate (3) in a predetermined direction. .

Next, the operation of this device will be explained.

In this embodiment, the upstream cooling roll (1) is at high speed, and the downstream cooling roll (2) is at low speed.

The molten steel (force) flowing through the molten steel channel (4) contacts the circumferential surface of the cooling roll (1) and is cooled to form a solidified layer (8).The solidified layer (8) is formed on the gap side as the cooling roll (1) rotates. It grows while moving to the cooling roll (2), comes into close contact with the similarly formed solidified layer 02) in the gap, and is cast as a steel plate (3). The moving speed of both solidified layers (8) α is the same as that of the cooling roll (
Since the peripheral speeds of 11 and (2) are different, both solidified layers (8
) and 02 during close contact, shearing deformation is applied between the rain layers to agitate the inside of the 'i14 plate (3) and prevent non-metallic segregation in the center. or,
By applying the shearing deformation in the gap, molten steel is replenished into the contracted portion during solidification, preventing the formation of cavities, and the shearing deformation refines the internal structure and improves mechanical properties. Furthermore, when the rotational speed of the cooling rolls (1) and (2) is increased to perform high-speed casting, the position where the interior of the steel plate (3) is completely solidified is not at the minimum part of the gap but further downstream. However, the cast steel plate (3) is peeled off from the cooling roll (1) by the foot guide (9), bent and pressed against the cooling roll (2), and moves while being wound around the cooling roll (2). . During this period of contact with the cooling roll (2), the steel plate (3) is cooled and completely solidified to the inside, without breakout.

Next, the steel plate (3) is peeled off from the cooling roll (2) by the foot guide OI and guided to a required position by the guide roll αυ.

In Example I, the upstream cooling roll was set at a high speed, but the downstream cooling roll may be set at a high speed, and the molten steel flow path may be further increased to lengthen the contact length between the downstream cooling roll and the molten steel. Of course, various changes may be made without departing from the gist of the present invention.

As described above, according to the present invention, it is possible to manufacture thinner strips than molten steel all at once, and high-speed casting is possible, and the casting speed can be increased to the extent that the rolling speed can be matched. Therefore, the casting line and rolling line can be made continuous, high-quality strips can be cast, the conventional heating process can be omitted, and the number of times the product is rolled can be significantly reduced.

[Brief explanation of the drawing]

The figure is a schematic explanatory diagram of a continuous strip casting apparatus according to the present invention. (11F2+ is a cooling roll, (4) is a molten steel flow path, (force is molten steel.

Claims (1)

[Claims] I) A molten steel flow path is formed by winding the molten steel around the outer periphery of one of two cooling rolls arranged in parallel with an appropriate gap maintained, and the molten steel is guided to the gap, and the circumferential speed of both rolls is controlled. A continuous strip casting device characterized by being configured to rotate at true speed.