KR19980048545A - Mini Mill Continuous Rolling Method - Google Patents

Abstract

In the present invention, a looper device is installed between the roughing mill and the finish rolling mill to control the amount of distribution, so that a sudden change in the amount of flow of the player and the roughing mill is absorbed so that the looper device absorbs a sudden change in the amount of distribution of the rolling mill and the finishing mill so as not to affect the distribution control of the finishing mill. The present invention relates to a method of continuous continuous rolling in a minimill that enables continuous continuous rolling.

The mini mill continuous rolling method of the present invention is adapted to absorb a sudden change in the flow volume of the machine 3 and the rough rolling mill 9 in the mini mill continuous rolling facility so as to appropriately control the flow volume in the finishing mill 13. A tension control looper device is installed between the rolling mill 9 and the finishing mill 13 so as to absorb a length of at least 600 mm, thereby controlling the amount of flow in the finishing mill.

Description

Mini Mill Continuous Rolling Method

In the present invention, a looper device is installed between the roughing mill and the finish rolling mill to control this, so that a sudden change in the amount of flow of the player and the roughing mill is controlled so that the looper absorbs and controls the distribution control of the finishing mill without affecting the distribution control. The present invention relates to a method of continuous continuous rolling in a minimill that enables continuous continuous rolling.

Products with high added value in the minimill process can be used as a cold rolled alternative if they can be rolled to a minimum thickness of 1.0 mm or less. To do this, unless rolling continuously, the plate does not run on the roller table at the top, but rather becomes fly (Flying) or enters between the rolls, making the operation impossible. In order to solve this problem, a method of rolling continuously in finish rolling by bar welding has been carried out as a known technique. However, in the mini mill, the slabs of 100 mm or less made from the machine can be produced continuously without welding equipment in the middle of the rough mill finish rolling mill.

However, there was a problem that the amount of change according to the circumferential speed of rolling during continuous rolling affects the finishing mill which is a post process.

In addition, it is necessary to secure the material temperature to the finish rolling mill and the winding machine even if the production capacity is secured in the mini mill. Therefore, high speed performance is required for this purpose, and the production speed should be more than 1 million tons / year, so the speed is 1.2-1.5mpm of the general player. It should be higher than 5.0mpm. At this time, the instantaneous fluctuation of the speed is about ± 0.3mpm / sec, the exit speed of the other roughing mill is generated 2mpm / sec and the finishing mill is fluctuated 30mpm / sec, so the maximum control amount of the finish rolling mill is 12mpm / sec. Control in the finishing mill becomes impossible.

The present invention has been made in order to solve the problems of the prior art described above, it is installed between the roughing mill and the finishing (graver) rolling mill to control the looper (Loorer) device that can absorb a length of at least 600mm or more, so It is an object of the present invention to provide a method of continuously rolling in a mini mill in which a rapid change in the amount of distribution of a rolling mill is absorbed by a looper device so as not to affect the distribution control of the finishing mill, thereby enabling continuous continuous rolling.

In order to achieve the above object, in the present invention, at least 600 mm length between the rough rolling mill and the finish rolling mill to absorb the sudden change of the flow rate of the player and the rough rolling mill in the mini mill continuous rolling mill so as to properly control the flow rate in the finish rolling mill. Provides a mini mill continuous rolling method characterized in that the tension control looper (Looper) device is installed to control the amount of distribution in the finishing mill to absorb.

1 is a view schematically showing a mini mill continuous rolling equipment of the present invention,

2 is a view schematically showing a looper device for controlling the tension between the roughing mill and the finishing mill constituting the present invention,

3 schematically shows a tension control flow in a looper device;

4 is a view showing the temperature change according to the continuous rolling in the mini mill.

* Description of the symbols for the main parts of the drawings *

1: ladle 2: tundish

3: rolling cycle 4: pendulum shearing machine

5: enco panel 6: induction heater

8, 12: Scale remover 9: Rough rolling mill

10: Tension control looper device 13: Finishing rolling mill

14: cooling stand 15: high speed shearing machine

16: Winder 17: Rolling mill work roll

18: Finishing Roll Work Roll

The invention will now be described in detail with reference to the accompanying drawings, in which preferred embodiments are shown.

In FIG. 1, the arrangement of a facility for showing a continuous rolling process flow in a minimill according to the present invention is schematically illustrated, in which a molten steel from the ladle 1 passes through a tundish 2. 3) through a slab, which is passed through a Pendulum Shear (4), an Enco Panel (5) of 20m length, and an Induction Heater of 10m length. After the temperature is raised while passing through (6), after the slab is descaled through the edger (7) and the descaler (8), the roughing mill (9) and the looper device for tension control (10) ), Through the Bar Shear (11), again through the scale controller (Descaler) 12, through the finishing mill (13), and then through the cooling table (14), high-speed shearing machine (15) After passing through, the winder 16 is wound to complete the final product.

In this continuous rolling process, the looper device 10 is installed for synchronizing the roughing mill and the finish rolling mill, and it is common to use a vertical hydraulic device that facilitates tension control. The looper device is controlled in such a manner that the total length is 2 m and the vertical length is controlled so that the absorption length is 600 mm rk.

As shown in FIG. 2, the tensioner looper device 10 includes pinch rolls 10a and 10b spaced apart from each other by a predetermined interval (for example, 2 m), and tension rolls 10c disposed at positions raised by a predetermined height therebetween. The hydraulic device 10d is coupled to the tension roll 10c to be interlocked, and the hydraulic device moves the tension roll 10c up and down by the upper and lower pressures P ₁ and P ₂ of the hydraulic device 10d. The board length interposed between the pinch rolls 10a and 10b is changed within a predetermined range to absorb a sudden increase in the amount of distribution. In other words, if the tension roll is raised so that 2.23m is normally interposed between 2.23m, the logistics volume of 600mm can be absorbed.

Specifically, the control process in this manner, as shown in the block of FIG. 3, the roll speed V _r of the last rough rolling mill 17 and the speed V _{f of the} finish rolling mill side roll 18 during the control. Is calculated by the plate speed calculation unit and calculates the plate speed (V _b1 )

V _b1 = (1 + f) V _r ............. (1)

And, if the finish rolling mill entrance plate speed (V _b2 ) is calculated,

V _b2 = (1-d) (V _f ) ............ (2)

(Where f is the advance rate of the roughing mill (-) and d is the reverse rate of the finishing mill (-)). At this time, the amount of change in the length of the plate between the looper of the looper device,

Δλ = ∫ (V _b1 -V _b2 ) dt ......... (3)

And the variation in tension is

ΔT = Eb / L Δλ ...... (4)

Where Eb is the elastic modulus of the bar and L is the length in millimeters between the rough and finish rolling mill.

Indicates the upper and lower pressure in the oil pressure unit (10d) to P _1, P _2, the normal at the time of continuous operation is P ₁ and a = P _2, when as much as △ λ length change is changed to (+) amount, and the P ₁ P ₂ , If you change it to (-), it becomes P ₁ P ₂

P ₁ -P ₂ = ΔT cos θ ......... (5)

(Theta is the angle between the looper device and the bar).

In the configuration of the mini-mill process, a temperature securing technique is required. As shown in FIG. 5, the temperature is 1288 ° C. at the entrance of the Enco Panel 5, and an induction heater 6 is used to secure the temperature of the post-process. ) Can be raised to 1347 ℃, and the temperature analysis in the subsequent process to ensure the temperature of 600 ℃ necessary in the winder.

Therefore, according to the continuous rolling method in the mini-mill of the present invention as described above, the sudden change in the amount of distribution of the machine and the rough rolling mill due to the playing circumferential speed during rolling is absorbed by the looper provided between the roughing mill and the finish rolling mill to finish the rolling mill. It can be controlled so as not to affect the logistics control, which prevents the plate from progressing on the roller table, flying or getting in between the rolls, and disturbing the work. The effect that can contribute to is obtained.

Claims (1)

The rough mill (9) and the finish mill (13) to absorb the sudden change of the flow rate of the machine (3) and the rough mill (9) in the mini mill continuous rolling facility so that the flow rate of the finish mill (13) can be properly controlled. Mini-mill continuous rolling method characterized in that the tension control looper (Looper) device is installed so as to absorb a length of at least 600mm in between to control the amount of flow in the finishing mill.