JPS6029580B2 - Continuous casting method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a continuous casting method.

Dummy bars used to guide coins during continuous casting in continuous casting equipment are removed from the casting line after passing through pinch rollers, and are kept on standby until the start of the next casting.

When starting the next casting, one method is to run this dummy bar backwards in the curved casting path and insert the dummy bar head into the mold from below.
This method requires a long casting preparation time. Therefore, as another method, a circulation method is adopted in which a dummy bar that is on standby is inserted from above the mold, thereby shortening the casting preparation time. However, on the other hand, a dual-purpose machine that can cast one slab or two blooms with one strand is desired. For example, as shown in Figure 1, the thickness t is 30
After casting slab 1 with 0 fence and medium L of 130 mm, next, as shown in Fig. 2, two blooms 2 with thickness T of 35 mm and medium 1 of 56 mm are cast. Let's think about the time. In this case, the continuous rust forming equipment has a mold and a support roller which are dedicated parts that can be replaced at once, and a guide roller and a pinch roller which are common parts. Therefore, when changing from the slab 1 to the bloom 2, the dedicated body part is replaced, and the vertical spacing of the support roller 3 in the common body part is changed to cope with the change in the thicknesses T and t mentioned above. First, as a dummy bar to close the bottom of the mold, two dummy bar heads 4A, 4 as shown in FIG. 3 are used.
A dummy bar 5 having B is used. Here, the mold for blooming is a twin mold with two openings by placing a steel plate in the center of the mold for slabs, which has one closed opening, by replacing the dedicated body part as described above.
This has been replaced. Therefore, the desired casting can be performed by inserting the dummy bar 5 from below prior to casting. However, as mentioned at the beginning,
Even if it is attempted to insert the dummy bar 5 from above in order to shorten the casting preparation time, it is impossible because it is a twin mode. For this reason, for blooming purposes, separate dummy bars 8 and 9 are prepared for each of the closed openings 6 and 7, as shown in Figure 4, so that the openings 6 and 7 can be accessed from above. It is possible to insert. However, for such medium and narrow dummy bars 8, 9, guide wheels are required on both sides of each dummy bar 8, 9. That is, as the dummy bars 8 and 9 swing from side to side, the portion of the bloom connected to the dummy bar head where the outer shell is not yet fully formed may be torn, and the unsolidified portion may leak out. However, in reality, as mentioned above, it is a machine that can also be used with slabs, so it cannot be installed only on the outside and cannot be installed on the inside. As described above, in a machine in which the dauber bar is inserted from above the mold and is used for both slab and bloom, the gap between the support rollers 3 is adjusted depending on the thickness each time the slab and bloom are switched. We have to make major changes. o The flume dummy bar cannot be guided inward, causing the dummy bar to swing.

There are problems such as.

The present invention provides a continuous casting method capable of solving the above problems, and one embodiment thereof will be described below with reference to FIGS. 5 and 6.

5 and 6 show support rollers 20, 20 of the union part used in the present invention.

These support rollers 20, 20 have a dummy bar for a slab (not shown) or a large diameter part 22, 22 supporting the slab 21 at the center, and a dummy bar for a bloom (not shown) or a bloom 23A at both ends. It has small depressions 24A and 24B that support 23B. Here, large diameter part D
The relationship between Tozu and Homobe d is that for the slab thickness t and bloom thickness T that are to be cast the most, [blood 10t = 10T
]. And the large diameter portions 22, 22 and the small diameter portions 24A, 2
The stepped side surfaces 25A and 25B with respect to 4B are used as a dummy bar for the bloom and an inner guide surface for the blooms 23A and 23B. 26 indicates a guide wheel.

Therefore, as shown in FIG. 5, a slab (or a dummy bar for the slab) 21 can be supported by the intermediate large support portion 22, and both sides of the slab 21 are provided by guide rods 26.
Here, the length 1 of the large support portion 22 is designed to support not the entire length L of the slab, but a necessary portion that is slightly narrower than the side solidification thickness, thereby supporting the small diameter portions 24A, 24B on both sides.
I have made the space as narrow as possible. On the other hand, two blooms (
The two blooming dummy bars (23A, 23B) inserted from above into the mold entrance are supported by the small depressions 24A, 24B on both sides, as shown in FIG. 25B, and the outer surface is guided by a guide wheel 26. And switching between both casting forms is done by Tobloom 23A, 23B and Slab 21.
When the relationship between the thickness of The support rollers 20, 20 may be adjusted slightly closer or farther apart by the amount of change. Flume 23A, 23
If the inside of B is such that bulging of the slab 21 (bulging of the mirror piece due to static pressure of steel) is not a problem, small diameter portions 24A and 24B may be formed in the intermediate portion as shown in FIG. As mentioned above, the pass level (level of the top surface of the roll in the horizontal section) changes by switching the common body part between slab use and bloom use, but this can be resolved by using rollers with the same shape for the rear conveyance roller table. obtain.

Furthermore, the circumferential speed of the loaf differs at the same rotation speed, but this can be solved by changing the setting of the motor rotation speed each time the switching is performed. According to the present invention described above, although the dummy bar is inserted from above the mold and the machine is a dual-purpose casting machine for slabs and blooms, the spacing between the support rollers is not adjusted at all when switching between slabs and blooms. This can be expected to significantly shorten the casting preparation time, and since the inner side of the bloom dummy bar can be guided by the step forming side, no wobbling of the bloom dummy bar will occur. ``Unforeseen situations such as leakage of unsolidified parts can be prevented.

[Brief explanation of drawings]

1 and 2 are a schematic front view showing a conventional example, FIG. 3 is a schematic plan view showing an example of a conventional dummy bar, FIG. 4 is a schematic front view showing one conventional use state, and FIG. 5 , FIG. 6 is a schematic front view showing one embodiment of the present invention, and FIG. 7 is a schematic front view showing another embodiment. 20...Support roller, 21...Slab, 22.
...Large diameter part, 23A, 23B... Flume, 24A, 24B... Small diameter part, 25A, 25B.
...Aspects of step formation, 26...Guidance theory. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1 The support roller is composed of a large diameter part and a pair of left and right small diameter parts, and the large diameter part supports the dummy bar for slabs and the slab to perform continuous casting, and the small diameter parts support the dummy bar for bloom and the bloom, respectively. A continuous casting method characterized in that continuous casting is carried out by supporting the bloom, and the dummy bar for the bloom and the inside of the bloom are guided by stepped side surfaces of a large diameter part and a small diameter part.