JPH0138585B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for continuously manufacturing sheet metal from molten metal.

Currently, the common method for producing thin plates from molten metal is to roll slabs, but it would be of great industrial value if thin plates could be produced directly from molten metal. In this case, from the viewpoint of productivity, it goes without saying that the thinner the plate, the higher the cooling rate must be, but it is difficult to actually cool a wide thin plate uniformly from the molten metal temperature at a high cooling rate. It's difficult.

In other words, a method is known in which molten metal is jetted from a nozzle onto the moving cooling surface of a metal cooling body and rapidly solidified to produce a rapidly solidified thin metal sheet, but this method has not been able to produce wide thin sheets so far. It is difficult. As the cooling body, single rolls, twin rolls, belts, drums, etc. are known. Among these methods, in the method of using a single roll or twin rolls as a cooling body, molten metal is jetted onto the rotating outer circumferential surface of the roll, rapidly cooled and solidified into a thin ribbon, and the contact time with the roll until it leaves the outer circumferential surface is extremely long. It has the disadvantage that it is short and the cooling by the rolls is not sufficient. In addition, the method of using a belt as a cooling body has the disadvantage that the belt is periodically subjected to heat loads from molten metal, which deforms the belt over time and makes it impossible to maintain a good desired shape. be. There is also known a method of manufacturing an amorphous metal thin plate using a drum as a cooling body. According to this method, molten metal is supplied to the inner cylindrical surface of a drum that rotates at high speed, and an ultra-thin ribbon is produced using centrifugal force. is superior in that the contact time is longer, but if the product plate thickness becomes thicker and it becomes necessary to lengthen the solidification time, it is necessary to increase the drum diameter. Since there is a limit to the rotation speed, in order to increase the contact time, it is necessary to slow down the rotation speed, and in this case, the effect of using centrifugal force is greatly reduced. That is, it becomes difficult to maintain uniform and sufficient contact between the inner cylindrical surface of the drum and the thin plate, and the thin plate cannot be cooled sufficiently. As a result, problems remain in that the thin plate may break during manufacturing, or even if manufacturing is possible, the flatness and surface properties of the obtained thin plate cannot be used as a product.

An object of the present invention is to provide a method for continuously manufacturing a thin plate from molten metal, which solves the problems of the conventionally known methods. can be achieved.

Next, the present invention will be explained with reference to the drawings.

According to the present invention, a metal ring 1 is used as the main cooling body.
Use. On the other hand, as a conventional method, a method is also known in which a ring is used as a cooling body, but this method requires that the ring be rotated at high speed to fully utilize the centrifugal force. However, according to the present invention, the thin plate 7 formed by rapidly solidifying the molten metal 8 supplied from the nozzle 2 onto the inner surface of the ring using the ring 1 and the squeeze roll 3 is attached to one or more sets of presser rolls. Since the ring 1 is compressed in the longitudinal direction while being pressed against the inner surface of the ring by the group 4, the ring 1 functions as a compression base. Therefore, the method of the present invention can be advantageously used even when the ring 1 is rotated at a low speed because the manufactured thin plate 7 has a large thickness and requires cooling for a long time. By the way, when using the rotating outer peripheral surface of a rotary cooling body as a cooling surface, it is necessary to apply tension to the thin plate in order to maintain long contact between the cooling surface and the thin plate being manufactured. It is difficult to apply tension to unsolidified or hot thin plates.

According to the present invention, a pool of the supplied molten metal is formed, and a thin plate is produced by narrowing down to a thickness corresponding to the initial plate thickness, and the drawing roll 3 is used to send the thin plate to the downstream side. Since it is rolled down to the thickness of the plate, it is possible to obtain a thin plate that is thicker and has a uniform thickness in the longitudinal direction, compared to the conventional method of simply spraying molten metal onto a cooling body. In the figure, 5 is a drive roll that rotates the ring 1, and 6 is a scraper that removes the thin plate from the ring.

In the present invention, the presser roll group 4 is used to control the moving speed of the thin plate after passing through the squeeze roll 3 to ensure cooling of the thin plate, and the presser roll itself does not have a great effect on heat removal. The function is to ensure the contact between the ring 1, which is the main cooling body, and the thin plate after passing through the squeeze roll 3. In other words, if the presser roll group 4 is not provided, the thin plate being cooled will not only rise from the inner surface of the annular ring due to thermal contraction, but will not only be difficult to cool, but will also locally rise from the inner surface of the annular ring. If this occurs, the cooling of the thin plate becomes uneven, resulting in irregularities in the shape. In particular, when the thin plate is produced and the atmosphere through which it passes is oxidizing, an oxidized layer is formed on the contact surface with the ring, making cooling of the thin plate increasingly uneven locally. Furthermore, even if a presser roll is provided, if a thin plate is manufactured without the force of the presser roll, the occurrence of the non-uniform cooling phenomenon described above cannot be avoided. In the present invention, at least one set of presser rolls may be provided, but as shown in the figure, multiple sets of presser rolls 4a may be provided.
It is preferable to provide 4c.

In order to avoid the occurrence of these phenomena, according to the present invention, between the squeezing roll 3 and the presser roll, in the illustrated example, the squeezing roll 3 and the presser roll 4a, the presser roll 4a, the presser roll 4b, and the presser roll 4b
The rolling force or rotational speed of each presser roll is changed so that a compressive stress capable of absorbing the amount of thermal contraction of the metal thin plate during cooling is applied in the longitudinal direction of the thin metal plate between the presser roll 4c and the presser roll 4c. The purpose is to control the sheet passing speed with the presser roll to ensure good contact between the thin sheet and the ring.

The reason why good contact between the thin plate and the ring can be realized by applying compressive stress in the longitudinal direction of the thin plate is as follows.

First, when the cast sheet passes through the presser roll, it is cooled between the squeeze roll and the presser roll or between the presser roll and the next presser roll, if no control is applied to the presser roll according to the present invention. During this process, thermal contraction occurs, creating tensile stresses in the sheet in its longitudinal direction. The thin plate then follows a straight path that deviates from the arc-shaped path line along the inner surface of the ring, and it becomes impossible to maintain contact between the thin plate and the inner surface of the ring.

To avoid the occurrence of such a phenomenon, it is necessary to
The thin plate is passed between two sets of rolls at a speed corresponding to the heat shrinkage that occurs in the thin plate passing between the set of rolls (for example, between the squeeze roll 3 and the presser roll 4a), and the thin plate is bent between the rolls to make contact with the inner surface of the ring. Just maintain contact.

Specifically, as mentioned above, the rotation speed and/or rolling force are adjusted, but when adjusting the rotation speed, there is a slip displacement, that is, a difference between the threading speed of the thin plate and the circumferential speed of the presser roll. The displacement caused by the resistance caused by the frictional force that occurs at times is used, and the plastic elongation of the material is used to adjust the rolling force. It is also possible to secure contact by applying compressive stress in the longitudinal direction of the thin plate by controlling the threading speed at . That is, one set or a plurality of sets of presser rolls must have at least one function of a rolling force control device or a rotation speed control device. The control amount is theoretically sufficient to compensate for the amount equivalent to thermal contraction, but according to the knowledge of the present inventors, in reality, compressive force is generated several times that amount, that is, in the longitudinal direction of the material. It is advantageous to choose such conditions. In other words, since the thin plate is subjected to a rolling force along the concave surface inside the ring, the control range until the material lifts up due to local buckling is quite wide on the rolling force side, and the conditions in the middle can be selected. stable operation can be achieved.

Next, the present invention will be explained with reference to examples.

Example A ring with a diameter of 1.2 m and a rotation speed of 20 rpm arranged as shown in Figure 1, a squeeze roll with a diameter of 20 cm driven in synchronization with the inner circumferential speed, and three 10 cm diameter rings
Using a device consisting of a presser roll, C: 0.005%,
A molten metal consisting of Si: 3.0%, Mn: 0.10%, balance Fe and unavoidable impurities was injected into a biting part consisting of a squeeze roll and a ring with a gap of 0.9 mm. The pressing force of the three presser rolls was adjusted so as to give an elongation rate of 1% to the material, respectively. The thin plate obtained in this way had significantly superior flatness and surface texture compared to the thin plate obtained without using the presser roll, or even the thin plate obtained when the presser roll was used but the rolling force adjustment described above was not performed. It was hot.

As described above, according to the present invention, since stable cooling can be performed for a long time while maintaining contact between the rapidly solidified thin plate and the cooling body, thin plates can be directly and continuously manufactured from molten metal.

[Brief explanation of drawings]

The figure is an explanatory longitudinal cross-sectional view of an apparatus that can be used to implement the present invention. 1... Annular ring, 2... Nozzle, 3... Squeezing roll, 4...
Presser roll group, 4a to 4c... Presser roll, 5... Drive roll, 6... Scraper, 7... Thin plate, 8
...molten metal.

Claims (1)

[Claims] 1. Molten metal is continuously supplied to a biting part formed by the inner surface of a rotating metal ring and the outer peripheral surface of a rotating squeeze roll disposed inside the ring. , a thin plate is produced by compressing and passing between the inside of the ring and the outer peripheral surface of a squeeze roll, and then passing between the inner surface of the ring and the outer peripheral surface of one or more sets of presser rolls. In this process, the heat of the thin sheet being cooled can be reduced by adjusting the rolling force and/or rotational speed of one set of presser rolls or all of multiple sets of presser rolls and controlling the threading speed when the sheet passes through the presser rolls. A method for continuously manufacturing a thin plate from molten metal, characterized by applying compressive stress in the longitudinal direction of the thin plate capable of absorbing the amount of shrinkage.