JPS59147750A - Continuous casting method - Google Patents

Abstract

PURPOSE:To prevent the generation of gaps between block molds and to produce a continuous cast billet having a good surface characteristics in a continuous casting device of a moving mold type by controlling the speed of pinch rolls for drawing the continuous casting billet so as to be made higher than the speed of a block mold feeder. CONSTITUTION:While upper and lower block molds 1 are fed in a direction A by feeders 4, a molten steel 3a is charged from a nozzle in the left end part into the molds to form a solidified shell 36 which is finally drawn as a continuously cast billet 3 by pinch rolls 6, 6. The speed of the feeders 4 is made higher than the speed of the rolls 6 to bring the adjacent block molds into tight contact with each other by making use of the friction force between the molds 1 and the solidified shell 3b of the billet 3 and to prevent the generation of gaps between the block molds, by which the billet 3 having an excellent surface characteristic without the fins to be formed in the gaps is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous casting method using a moving mold.

Figures 1 and 1 show an apparatus for carrying out this type of continuous casting method. Figure 1 shows an example of an apparatus in which block molds 1 are arranged in an endless track, and Figure 2 shows a block mold 1. An example in which the mold 1 is not connected is shown. In these figures, numeral 2 indicates a tundish containing molten steel 3&, 3b
is a shell in which the molten steel 3a is solidified, fc4 is a feeding device that sends the block mold 1 in the casting direction A, 5 is a support roll that supports the cast slab 3, and 6 is a support roll that pulls out the slab 3. This is a pinch roll, and is operated together with the feed device 4 by a drive device (not shown). , 7 are guide rolls.

When performing continuous casting using these devices, each block mold 1 is moved in the casting direction A by the feeding device 4, and the molten steel 3a is introduced into the mold space S formed by the block mold 1 from one side (left side in the figure). is poured, and the slab 3 is pulled out from the other side (the right side in the figure) with a pinch roll 6 to be cast. At that time, conventionally, the speed of the feeding device 4 and the speed of pulling out the pinch roll 6 were made the same. .

However, in such a conventional method, as shown in FIG. 3, a gap B is created between the contact surfaces of individual adjacent block molds 1 forming a mold space S, and the molten steel 3 &
As a result, so-called IJ 3 c is generated on the surface of the slab 3, resulting in deterioration of the surface quality of the slab 3.

The present invention solves the above conventional problems by controlling the feeding speed of the block mold to be faster than the speed of the pinch rolls, and utilizes the frictional force between the block mold and the solidified shell of the slab. An object of the present invention is to provide a continuous casting method in which adjacent block molds are brought into close contact with each other without creating a gap between the block molds.

Hereinafter, the present invention will be explained in detail based on the drawings.

The continuous casting method of the present invention is similar to the conventional method as shown in Fig. 1 or 2.
It is implemented by the apparatus shown as an example in the figure.

When continuous casting is performed using these devices, the block mold 1 is moved in the casting direction A, the molten steel 3a is poured into the mold space S, and the cast slab 3 is pulled out by the pinch rolls 6. Same as the conventional method, but in this case, in the method of the present invention, the speed of the feeding device 4 is controlled to be faster than the speed of the pinch roll 6, and the casting direction A is controlled.
Adjacent block molds 1 are brought into close contact with each other to prevent the occurrence of a gap B between the block molds 1.

That is, if the speed of the feeding device 4 is controlled to be faster than the speed of the pinch rolls 6, the block mold 1 tends to slip between itself and the solidified shell 3b. However,
An iron static pressure P corresponding to the head of the molten steel 3a in the tundish 2 acts on the shell 3b. Since the strength of the shell 3b is insufficient to withstand this iron static pressure P, the block mold 1 ends up receiving the force generated by this iron static pressure P. Therefore, a frictional force acts between the shell 3b and the block mold 1 to prevent slipping. Since the feeding device 4 feeds the block molds 1 against this frictional force, a contact force acts between the block molds 1 adjacent to each other in the casting direction A, and the block molds 1 move in close contact with each other. .

When the block mold 1 is sent by the feeding device [IT4], the block mold 1 that comes into contact with the shell 3b is more likely to be moved forward than the block mold 1 on the left side of the figure, and it is difficult to move, and it is on the injection side of the molten steel 3a, that is, the tundish 2 side. The closer it gets to , the stronger the contact force between the block molds. therefore,
Block mold 1
This is advantageous because the adhesion between them increases and the gap B can be more reliably prevented.

Incidentally, in order to make the feeding speed of the block mold 1 faster than the speed of the pinch roll 6, it is sufficient to control the rotational speed of a driving source such as a motor. Further, in the figure, seven pairs of upper and lower pinch rolls 6 are arranged, and both the upper and lower sides are connected to the drive source, but only one of the upper and lower sides may be connected to the drive source. Furthermore, it goes without saying that the method of the present invention can be applied to moving mold type continuous casting apparatuses of other structures.

As described above, according to the present invention, the frictional force generated between the block mold and the solidified shell is reduced by controlling the speed of the feeding device to be faster than the speed of the pinch rolls during continuous casting. It is possible to apply a contact force between adjacent block molds in the casting direction, prevent gaps between the block molds, and cast slabs with good surface properties. Furthermore, there is an advantage that the adhesion between the block molds is greatest in the areas where prevention of gaps is most necessary. Furthermore, there is no need to install any special equipment to prevent gaps.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing an example of an apparatus for carrying out the continuous casting method, Fig. 2 is a longitudinal cross-sectional view showing another example of the apparatus, and Fig. 3 is a longitudinal cross-sectional view for explaining the conventional method. The top view and FIG. 9 are longitudinal sectional views for explaining the present invention in detail. l...Block mold, 3a-... Molten steel, 3
b... Chaosle, 3... Slab, 4...
...Feeding device, 6...Pinch roll, S...
...Mold space, applicant Ishikawajima Harima Heavy Industries Co., Ltd.

Claims (1)

[Claims] Multiple block molds are connected to form a continuous mold space, and while these block molds are moved, molten steel is poured into one side of the mold space, and slabs are pulled out from the other side with pinch rolls to perform continuous casting. A continuous casting method, characterized in that the feeding speed of the block mold is controlled to be faster than the speed of the pinch rolls.