JPS63157750A - Strip production apparatus - Google Patents

Abstract

PURPOSE:To enable rolling without cutting the continuously cast slab on the way and to produce a steel under good thermal efficiency and low cost by arranging a cast slab accumulator between continuous casting machine and rolling mill at the time of rolling the cast slab for continuous casting machine by directly rolling mill. CONSTITUTION:The continuously cast slab 6 is produced from molten steel by the continuous casting apparatus 1 and a straightening roll 7, and rolled into a steel strip by rolling mill group 2 through a broadside rolling 8, to wind to a coiler 3. The tension of cast slab in the continuous casting apparatus 1 is zero or a little, but in the cast slab 5 at the rolling mill group 2, the tension is always developed and in case this tension is developed to the continuously cast slab 6 drawn at the constant velocity, as the accident, such as internal crack, surface crack, breakout, etc., is occurred in the cast slab 6, the accumulator 9 is arranged in front of the rolling mill group 2, to absorb the difference between the casting velocity of continuous casting apparatus 1 and the velocity of cast slab 5 at the rolling mill group by the accumulator 9. Thus, the tension of cast slab loaded by the rolling mill 2 is not reached the continuous casting apparatus 1 and the accident, such as internal crack, surface crack, breakout, etc., caused by developing the force tension to the continuously cast slab 6 is not occurred, and it can be rolled by the directly rolling mill 2.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a V5 manufacturing method for plate materials, and in particular, a plate material that is manufactured at low cost by directly connecting a continuous casting line and a rolling line! ! The present invention relates to a plate manufacturing apparatus suitable for safely manufacturing high-quality plates using two manufacturing methods.

[Conventional technology]

In recent years, board material'i! There is a strong demand for energy saving and cost reduction for five-piece structures, and research on manufacturing methods for plate materials is being actively conducted. In particular, manufacturing processes that directly connect continuous casting and rolling are attracting a lot of attention from the viewpoint of resource and energy conservation.

As for the traditional continuous casting rolling direct coupling process.

For example, as discussed in Steel Manufacturing Research No. 310 (1982), pages 251 to 263, a steel billet is first cut at the exit side of a continuous casting machine, and the cut billet is kept warm and sent to the rolling process. A method of transporting and manufacturing plate materials is used. The biggest advantage of using the continuous casting and rolling process is that by rolling the steel material without cooling it after casting, the thermal energy that would otherwise be lost due to cooling can be used effectively, reducing production costs. be.

It has been found that the consistent method of manufacturing plate material has the following serious drawbacks.

In other words, in a continuous casting machine, the casting is soft.

Applying tension to this is thought to be one of the causes of internal cracks 1 surface cracks, etc.
No. (1984), pages 1 to 12, there is even a concept of applying compressive force on the contrary. On the other hand, in order to make the rolling process more compact, it is necessary to increase the processing rate of the material per rolling mill, and to do this, it is necessary to apply tension to the plate material and keep it in a state where it is easy to deform. becomes important. Therefore, as shown in FIG. 3, the tension conditions required for the steel billet differ significantly between the continuous casting machine and the rolling process.

If the continuous casting machine and the rolling process are directly connected, the configuration will be as shown in Fig. 4, but in the second rolling mill group, tension is always applied to the slab, and in the first continuous casting machine, the tension is zero. or hold a small value. The tension in the steel billet in the rolling mill group 2 is controlled primarily by increasing or decreasing the roll speed of the work rolls 4 of the rolling mill. Therefore, in order to maintain tension during rolling, the speed of the work rolls 4 is constantly increased and decreased, and the speed of the billet 5 is also increased and decreased. However, the casting speed of the continuous casting machine 1 is constant, and as the speed of the slab 5 increases or decreases, tension due to the difference in speed between the casting speed and the slab 5 is applied to the slab 6 in the continuous casting machine.

As mentioned above, if tension is applied to the slab in a continuous casting machine, not only will it cause serious defects in product quality such as internal cracks and surface cracks, but it can also cause breakouts in which the slab collapses and the molten metal scatters. This will also pose a serious hindrance to safe operations.

[Problem that the invention seeks to solve]

For this reason, conventionally, a steel billet was cut on the output side of a continuous casting machine and the cut steel billet was transported to a rolling process to produce a plate material. However, with this method, a sufficient energy saving effect cannot be expected due to heat dissipation during transportation, and additional equipment such as a transportation line and steel cutting machine is required, making it difficult to downsize production equipment and reducing manufacturing costs. There were problems such as not being able to expect sufficient reduction.

The present invention directly connects a continuous casting machine and a plate rolling machine to ensure safe operation in the plate manufacturing process of producing plates from molten metal without cutting the billet midway, and to produce high-quality plates at low cost. The purpose of the present invention is to provide a layout of manufacturing equipment and a manufacturing method that can be manufactured at low cost.

[Means for solving problems]

An object of the present invention is to directly connect a continuous casting machine and a plate rolling mill, so that the continuous casting machine and the rolling mill can be used in a plate manufacturing process in which plates are continuously manufactured from molten metal without cutting the billet midway. This is achieved by placing a billet accumulator in between.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

The plate manufacturing process shown in FIG. 1 is composed of a continuous casting machine 1, a rolling mill group 2, a winding machine 3, a straightening roll 7, a width rolling mill 8, and a billet accumulator 9. Tension is always applied to the steel billet, and in the continuous casting machine 1, the tension is maintained at zero or a small value. The tension in the steel billet in the rolling mill group 2 is adjusted by increasing or decreasing the roll speed of the work rolls 4 of the rolling mill. Therefore, in order to maintain tension at all times during rolling, the roll speed of the work rolls 4 is constantly increased and decreased, and the speed of the steel billet 5 is also increased and decreased.

On the other hand, the casting speed of the continuous casting machine 1 is constant, and a speed difference occurs between the steel billet 5 and the slab 6 due to the speed difference between the casting speed and the billet speed. This speed difference becomes the amount of slack in the plate in the steel billet accumulator 9 and is absorbed. That is, when the speed of the slab 5 is faster than the speed of the slab 6, the amount of slack of the plate in the slab accumulator 9 decreases, and conversely, the amount of slack of the plate in the slab accumulator 9 decreases.
When the speed of the slab 6 is lower than the speed of the slab 6, the amount of slack of the plate in the slab accumulator 9 increases, and the speed difference is absorbed. Therefore, the tension of the steel billet loaded in rolling mill group 2 is not transmitted to the casting machine, making it possible to consistently manufacture stable plates from unrolling to rolling. This makes it possible to prevent defects.

FIG. 2 shows another embodiment of the invention. The plate manufacturing method shown in Fig. 2 includes a continuous casting machine 1, a rolling mill group 2, and a winding machine 3.
It is composed of a straightening roll 7, a width rolling mill 8, a billet accumulator 9, a billet slack amount detector 10 installed in the billet accumulator 9, and a rolling speed controller 11. In the continuous U-making machine 1, the tension of the steel billet is maintained at zero or a small value, and in the rolling mill group 2, tension is always applied to the steel billet. The tension of the steel strip in the rolling mill group 2 is controlled by increasing or decreasing the roll speed of the work rolls 4 of each rolling mill and adjusting the roll speed difference between the rolls. Therefore, the tension is always applied during rolling. Therefore, the roll speed of the work roll 4 is repeatedly increased and decreased, and the speed of the steel billet 5 is also increased and decreased.

On the other hand, the casting speed of the continuous casting machine 1 is constant, and a speed difference occurs between the steel slab 5 and the slab 6. This speed difference becomes the amount of slack in the steel billet in the billet accumulator 9 and is absorbed. That is, when the speed of the steel billet 5 is faster than the speed of the slab 6, the amount of slack of the steel billet in the billet accumulator 9 decreases. The decrease in the amount of slack in the steel billet is detected by the amount of slack in the steel billet detector 10, and a detection signal is sent to the rolling speed controller 11. The rolling speed controller 11 that has received the detection signal gives a deceleration signal to the roll drive motor 12, and the roll speed is decreased.

As a result, the steel billet 5 is decelerated, and the amount of slack in the steel billet increases and returns to its original state. Conversely, when the speed of the steel billet 5 is slower than the speed of the slab 6, the amount of slack in the steel billet in the billet accumulator 9 increases, the increase is detected by the billet slack amount detector 10, and the detection signal is is sent to the rolling speed controller 11. Rolling speed controller 1 that received the detection signal
1 gives a speed increase signal to the roll drive motor 12, and the roll speed increases. As a result, the steel billet 5 accelerates, the amount of slack in the steel billet increases, and returns to its original state.1 According to another embodiment of the present invention, as described above, a constant amount of slack in the steel billet is always stored in the billet accumulator 9. is ensured, and the tension is maintained without being propagated from the steel piece 5 to the steel piece 6. Therefore, consistent and stable manufacturing is possible from casting to rolling, and quality defects such as internal cracks and surface cracks can be prevented. Further, according to another embodiment of the present invention, since the amount of slack in the steel billet accumulator 9 is kept constant, the steel billet accumulator can also be small-sized, which is economical.

〔Effect of the invention〕

As described above, the present invention has the advantage that by directly connecting a continuous casting machine and a rolling mill group, it is possible to consistently produce high-quality plate materials from molten metal to plate materials at low cost and stably.

[Brief explanation of the drawing]

Fig. 1 is a side view showing one embodiment of the present invention, Fig. 2 is a side view showing another embodiment of the present invention, and Fig. 3 is a tension gap between a slab and a steel slab in a continuous casting machine and rolling process. FIG. 4 is a conventional configuration diagram in which a continuous casting machine and a rolling mill are directly connected.

Claims (1)

[Claims] 1. In the plate manufacturing process, in which the continuous casting machine and the plate rolling mill are directly connected, and the plate material is manufactured continuously from molten metal without cutting the steel billet midway, the steel billet is placed between the continuous casting machine and the rolling machine. A board manufacturing device characterized by having an accumulator arranged therein.