JPS6057413B2 - Double-end open mold for continuous metal casting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the method of attaching a vibration generator to a mold for applying high frequency vibrations to the mold in a mold for continuously casting molten metal.

Conventionally, when continuously casting molten metal, in order to prevent seizing on the contact surface between the mold and solidified metal or to promote lubrication, the mold was cast at a rate of several tens to hundreds of meters per minute. A method of performing reciprocating motion with an amplitude of (hereinafter referred to as the reciprocating vibration method) is generally practiced.

In addition, there is a method of reciprocating in the direction intersecting the slab, that is, the circumferential direction of the round ingot (hereinafter referred to as the rocking method).
There is also a West German patent 896988; 195 yen). Furthermore, a method of applying vibration to the mold at a rate of 5 to 30 cycles/second (hereinafter referred to as the "vibration method") has recently been developed.

On the other hand, the present inventors have previously devised a method of promoting lubrication by applying high frequency vibration of 5 to 50 KHz to the mold. Now, the advantages and disadvantages of such a method are as follows. First, in the reciprocating vibration method, striped patterns (usually referred to as oscillation marks) are formed on the surface of the solidified metal lump due to the reciprocating vibration of the mold, causing surface defects.

However, this method is widely practiced because it is easy to implement and can be applied to flat molds and round molds. Furthermore, the locking method is not general because its application is limited to round molds. The vibration method has the disadvantage that the slab also vibrates, which affects the quality of the slab and limits its applications. Furthermore, in the method of applying high-frequency vibrations of 5 to 50 KHz to the mold, conventionally, vibration energy was applied to the entire mold including the cooling box and attached parts such as cooling piping, so a large amount of incident energy was required.
The present invention was made to solve these problems, and it makes the oscillation mark on the slab lighter, reduces surface flaws, can be applied to a variety of mold shapes, and is This provides a mold that can reduce the amount of energy.

That is, the present invention, in a mold with both ends open for continuously casting molten metal, separates the part of the mold that comes into contact with the metal to be cast (hereinafter referred to as the mold moving part) from the other part connected to it, and separates both parts. The structure is such that they are connected by a coupling means that blocks high-frequency vibrations, and the mold moving part has a frequency of 5 to
This relates to a metal casting mold which is designed to apply vibrations with an amplitude of 100 μm or less (50 KHz). Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 shows a conventional high-frequency vibration mold invented by the present inventors. Vibration is applied to the molten metal casting mold 6 via the connecting rod 2. In this case, the cooling box of the mold and the mold moving part have an integral structure in terms of high frequency vibration, and the incident high frequency vibration energy is transmitted to the cooling box other than the mold moving part. In order to transmit the incident energy to the mold moving part as much as possible, the present invention is constructed as shown in FIG. In FIG. 2, the mold operating section 4 is separated by a cooling box 5 and a backing 9 in terms of high frequency vibration.

The high frequency vibrations are transmitted to the mold operating section 4 via the vibration connecting rod 2. In the present invention, the frequency of high-frequency vibration applied to the mold moving part is set to 5 to 50 KHz, 100 pm amplitude,
It is necessary to keep it within the following range.

This is a condition that reduces the friction coefficient of the inner wall of the mold to a required level and does not cause any trouble to the water seal mechanism between the mold moving part and the water cooling box. In addition, in the low frequency range of less than 5K ratio, it will generate a loud noise and cannot be used in the working environment, and in the frequency range of more than 50KHz, it will not work as mechanical vibration and will reduce the friction between the mold and the slab. cannot be reduced. If the amplitude exceeds 100 pm, it becomes impossible to use a backing material in the vibration isolation means, such as the O-ring area, causing problems such as water leakage. Next, examples of the present invention will be described. By each method shown in Figs. 1 and 2, a water-cooled copper mold (the total weight of the mold in Fig. 1 is 30 kg, the weight of the mold moving part in Fig. 2 is 5 kg) is used, and Power 2 via the connecting rod
KW1 vibration frequency 18KHZ1 vibration amplitude of connecting rod 40μ
m high frequency! Vibration was applied.

All connections between the vibrator, the vibrating connecting rod, and the mold were tightened with screws. Also, the vibration connecting rod is 40Tsnφ
It was hot. The mold has an amplitude of 5w along the mold pulling direction!
Vertical reciprocating vibration was performed at t. While ordinary carbon steel was being cast into this mold, an 80 Twt square steel material was cast at a drawing speed of 3 m/min. In this casting, the force applied to the vertically vibrating rod of the mold was measured to investigate the influence of the mold shown in FIGS. 1 and 2, and the results shown in FIG. 3 were obtained. In other words, when the vibration power of high-frequency vibration is increased, the force applied to the rod decreases, and the degree of this decrease is greater with mold B shown in Figure 2 than with mold A shown in Figure 1. I understand. That is, according to the present invention, the frictional force between the mold and the slab can be reduced with a small amount of power. It goes without saying that the present invention can also be used in combination with the use of a lubricant and the reciprocating vibration of the mold.

In addition, there are no restrictions on the material or shape of the continuous casting mold, and the continuous means of the vibrating rod can be welded, screwed, etc., and the vibrating rod can be used in a direction perpendicular to the mold and in the direction of drawing out the slab. There are cases where connections can be made from two directions. Furthermore, for a rectangular mold, high-frequency vibrations can be applied to two or four opposing sides. However, it is necessary to make the frequency and phase of the applied high-frequency vibrations the same.

[Brief explanation of drawings]

FIG. 1 shows a conventional high-frequency vibration imparting mold, and FIG. 2 shows a mold according to the present invention. DESCRIPTION OF SYMBOLS 1... Vibrator, 2... Vibration connecting rod, 3... High frequency vibration generator electrical equipment, 4... Mold operating part, 5... Cooling box, 6... Mold, 7... - Cooling water inlet, 8... Cooling water outlet, 9... Backing, 10... Vertical vibration rod.

Claims (1)

[Claims] 1 Consists of a mold part (mold moving part) in contact with the metal to be cast and another mold part connected to it, which are connected with means for vibration isolation, and the mold part in contact with the metal to be cast has a frequency of 5 to 50 KHz. , a double-end open mold for continuous casting of metal, which is equipped with a high-frequency vibration generator with an amplitude of 100 μm or less.