CN116000257A - Device and method for large reduction of sector section of slab - Google Patents

Abstract

The invention provides a device and a method for large reduction of a sector section of a slab, comprising: a reduction roller and a reduction control device; the reduction roller includes at least two pairs of driving rollers and a pair of driving rollers arranged between adjacent driving rollers Free rollers; each pair of driving rollers includes an upper driving roller and a lower driving roller, each pair of free rollers includes an upper free roller and a lower free roller; each pair of driving rollers is connected with a transmission device, and the upper driving roller and the lower driving roller are driven by the transmission device The driving roller rotates; the pressing control device includes a first pressing cylinder arranged on the upper driving roller and a second pressing cylinder arranged on the upper free roller. The present invention can solve the problems of high precision requirement for the pressing position, high requirement for the bearing capacity of the frame of the sector section, and prone to bulge phenomenon in the current large reduction technology of the slab sector.

Description

Device and method for large reduction of sector section of slab

technical field

The invention relates to the technical field of iron and steel metallurgy, and more specifically, to a device and method for large reduction of a segment of a slab.

Background technique

In order to improve the central porosity of slabs and adopt smaller compression ratios to produce thick slabs, large reductions are adopted in the continuous casting process at home and abroad. In order to implement this technology, work is done on the basis of existing slab segments. One method is to increase the rigidity of the segment body, increase the clamping cylinder capacity of the segment, and use the entire segment to implement a large reduction. The segment structure of this method is different from that of the conventional slab segment. Essentially different. Another way is to carry out the reduction by a pair of rollers in the sector section. In this method, the diameter of the rollers is very large to avoid deformation of the rollers.

At present, there are many problems and deficiencies in the implementation of large compression in these types of sectors:

1) Due to the large amount of reduction, generally 10-15mm, the frame of the fan-shaped section is subjected to a large force, reaching thousands of tons. The conventional structure is difficult to guarantee the accuracy of the frame, and permanent deformation will occur after a period of use;

2) When one of the pair of rollers is used for pressing, the pressing position needs to be very accurate, but the solidification end point of the fan-shaped section often has a large change. In this scheme, the pressing position is usually when the slab is basically fully solidified, so the pressing force is very large. In order to avoid deformation, the selected roll diameter is generally about 700mm;

3) Due to the large diameter of the roll and the large distance between the front and rear rolls, when the pulling speed is high, it is easy to bulge and cause cracks, so the applicability of this solution is not strong.

To sum up, there are problems such as high requirements on the accuracy of the pressing position, high requirements on the bearing capacity of the frame of the sector section, and prone to bulging when using the existing technology.

Contents of the invention

In view of the above problems, the purpose of the present invention is to provide a large reduction device and method for a slab sector to solve the problem of high accuracy of the position of the slab sector in the current large reduction technology for the slab sector. The frame has high requirements for bearing capacity and is prone to problems such as bulging.

The present invention provides a slab segment large reduction device, comprising: a reduction roller and a reduction control device; wherein, the reduction roller includes at least two pairs of driving rollers and a pair of driving rollers arranged between adjacent driving rollers. A pair of free rollers; each pair of driving rollers includes an upper driving roller and a lower driving roller, and each pair of free rollers includes an upper free roller and a lower free roller; each pair of driving rollers is connected to a transmission device, and the transmission device drives the The upper driving roller and the lower driving roller rotate; the pressing control device includes a first pressing cylinder arranged on the upper driving roller and a second pressing cylinder arranged on the upper free roller.

In addition, preferably, the pressing rollers include three pairs of driving rollers and two pairs of free rollers.

In addition, preferably, the driving roller has a diameter of 400-450 mm; and/or, the free roller has a diameter of 400-450 mm.

In addition, a preferred solution is that the pressure values of the driving roller and the free roller are both 200-300 tons.

In addition, preferably, the first pressing cylinder is arranged at both ends of each pair of driving rollers; and/or, the second pressing cylinder is arranged at both ends of each pair of free rollers.

In addition, the preferred solution is that a first displacement sensor is provided in the first pressing cylinder; the upper driving roller presses down the segment of the slab through the moving displacement value acquired by the first displacement sensor; And/or, a second displacement sensor is arranged in the second pressing cylinder; the upper free roller presses down the segment of the cast slab through the movement displacement value acquired by the second displacement sensor.

In addition, the preferred solution is that a first pressure sensor is provided in the first pressing cylinder; the upper driving roller presses down the segment of the slab through the pressure value obtained by the first pressure sensor and/or, a second pressure sensor is provided in the second pressing cylinder; the upper free roller presses down the segment of the billet through the pressure value obtained by the second pressure sensor.

In addition, a preferred solution is that the distance between adjacent driving rollers and free rollers is 430-480 mm.

The present invention provides a method for large reduction of a segment of a slab, using the device for large reduction of a segment of a slab to perform large reduction of a segment of a slab, comprising the following steps:

According to the interval position of the slab solid phase ratio of 0.3 to 0.8, determine the casting resistance received by the large reduction device of the sector section of the slab when the large reduction is performed;

Determine the initial value of the transmission device according to the casting resistance, and complete the large reduction of the segment of the slab; wherein, when the reduction rollers that perform a large reduction on the segment of the slab are any pair of driving rollers, Then, the transmission device connected with the rest of the drive rollers jointly provides pressure for the casting resistance, and the free rollers that have not implemented a large reduction adopt hot slab pressing to press the slab; When the pressed down roller is a free roller, the transmission device connected to the driving roller jointly provides pressure for the drawing resistance.

In addition, the preferred solution is that the calculation formula of the drawing resistance suffered by the large reduction device of the sector section of the slab during the large reduction is: F=2σδ(2Rh-h ² )/R;

Among them, σ is the average deformation resistance, δ is the thickness of the slab; R is the radius of the reduction roller; h is half of the reduction, and F is the casting resistance generated by a pair of reduction rollers.

From the above technical solutions, it can be seen that the fan-shaped section large-reduction device and method of the slab provided by the present invention are provided with at least two pairs of driving rollers and free rollers arranged between adjacent driving rollers in the fan-shaped section, and each pair The pressing rollers are separately equipped with pressing cylinders, so that each pair of pressing rollers can be individually pressed. Since multiple pairs of pressing rollers work together, the roll diameter of the individual pressing rollers can be reduced, and the adjacent pressing rollers The roll distance between the lower rolls is small, which can effectively avoid the appearance of bulging, and the reduction can be carried out within the range of the solid phase ratio. Since the slab is not fully solidified, the required reduction force is small, which reduces the impact on the sector. Rigidity requirements of the frame; different from the conventional segment with only one pair of driving rollers, the present invention uses at least two pairs of driving rollers, and only one pair of the driving rollers is used in the present invention due to the large drawing resistance during the large reduction. According to the change of the solid phase rate in the center of the slab, when the driving roll or free roll is used for single-roll rolling, the other driving rolls will give corresponding pressure to provide a large enough driving force to effectively avoid stagnation. The emergence of blank phenomenon.

To the accomplishment of the above and related ends, one or more aspects of the invention include the features hereinafter described in detail. The following description and accompanying drawings detail certain exemplary aspects of the invention. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Furthermore, the invention is intended to include all such aspects and their equivalents.

Description of drawings

Other objects and results of the present invention will become clearer and easier to understand by referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention. In the attached picture:

Fig. 1 is a structural schematic diagram of a large sector section large pressing device of a slab according to an embodiment of the present invention;

2 is a schematic structural view of a driving roller according to an embodiment of the present invention;

Fig. 3 is a structural schematic diagram of the connection between the pressing roller and the transmission device according to the embodiment of the present invention.

Fig. 4 is a schematic flowchart of a method for large-scale reduction of a segment of a slab according to an embodiment of the present invention.

In the drawings, 1-driving roller, 11-upper driving roller, 12-lower driving roller, 2-free roller, 21-upper free roller, 22-lower free roller, 3-transmission device, 41-first pressing Cylinder, 42 - Second Depression Cylinder.

The same reference numerals indicate similar or corresponding features or functions in the drawings.

Detailed ways

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that these embodiments may be practiced without these specific details.

Aiming at the problems that the current large reduction technology for the slab segment has high requirements for the accuracy of the reduction position, high requirements for the frame bearing capacity of the segment, and prone to bulging phenomenon in the current large reduction technology of the slab segment proposed above, a slab reduction technology is proposed. A device and a method for large reduction of a segment.

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

In order to illustrate the device and method for large reduction of a sector of a slab provided by the present invention, Fig. 1 shows the structure of a large reduction device of a sector of a slab according to an embodiment of the present invention; The structure of the driving roller of the example; FIG. 3 shows the structure of the connection between the pressing roller and the transmission device according to the embodiment of the present invention. Fig. 4 shows the process flow of the method for large reduction of a segment of a slab according to an embodiment of the present invention.

As shown in Fig. 1 to Fig. 4 together, the fan-shaped section large reduction device of the slab provided by the present invention includes: a reduction roller and a reduction control device; wherein, the reduction roller includes at least two pairs of driving rollers 1 and is arranged on A pair of free rollers 2 between adjacent driving rollers 1; Every pair of driving rollers 1 all comprises upper driving rollers 11 and lower driving rollers 12, and every pair of free rollers 2 all comprises upper free rollers 21 and lower free rollers 22; The driving roller 1 is connected with a transmission device 3, which drives the upper driving roller 11 and the lower driving roller 12 to rotate through the transmission device 3; the pressing control device includes a first pressing cylinder 41 arranged on the upper driving roller 11 and an upper The second depressing cylinder 42 on the free roller 21.

By arranging at least two pairs of driving rollers 1 and free rollers 2 arranged between adjacent driving rollers 1 in the sector section, and each pair of pressing rollers 1 is provided with a pressing cylinder independently, so that each pair of pressing rollers can The reduction is carried out separately. Since multiple pairs of reduction rollers work together, the diameter of the individual reduction roller can be reduced, and the distance between the adjacent reduction rollers is small, which can effectively avoid the appearance of belly. The reduction is carried out within the range of the solid phase ratio. Since the slab is not fully solidified, the reduction force required is small, which reduces the rigidity requirements for the sector frame; The casting resistance is relatively large when the reduction is large. The present invention uses at least two pairs of driving rollers 1. When the reduction is performed, only one pair of the pressing rollers is used to perform the reduction. When roll 1 or free roll 2 performs single-roll pressing, other driving rolls 1 give corresponding pressure to provide sufficient driving force and effectively avoid the phenomenon of billet stagnation.

As a preferred solution of the present invention, the pressing rolls include three pairs of drive rolls 1 and two pairs of free rolls 2 . In the preferred solution of the present invention, 5 pairs of pressing rollers are used, among which three pairs of driving rollers 1 and two pairs of free rollers 2 can achieve the best combination effect, and at the same time, the occupied space is more reasonable.

As a preferred solution of the present invention, the diameter of the driving roller 1 is 400-450 mm; and/or, the diameter of the free roller 2 is 400-450 mm. The roll diameters of the driving tube 1 and the free roll 2 are smaller than the roll diameters of a pile of drive rolls used in the prior art, and the small roll diameters help to reduce the roll distance between adjacent rolls and avoid bulging.

The pressure values of the drive roller 1 and the free roller 2 are both 200-300 tons. The pressure value is lower than that of a pair of drive rollers, avoiding damage to the frame of the segment.

As a preferred solution of the present invention, the first pressing cylinder 41 is arranged at both ends of each pair of driving rollers 1 ; and/or, the second pressing cylinder 42 is arranged at both ends of each pair of free rollers 2 . The two ends of the pressing roller are pressed simultaneously, and the pressing effect is better. Each pair of pressing rollers can be controlled to implement individual pressing.

As a preferred solution of the present invention, a first displacement sensor is arranged in the first pressing cylinder 41; the upper driving roller 11 presses down the segment of the cast slab through the moving displacement value acquired by the first displacement sensor; and/or A second displacement sensor is arranged in the second pressing cylinder 42; the upper free roller 21 presses down the segment of the billet through the moving displacement value acquired by the second displacement sensor. The pressing displacement value of the pressing roller can be transmitted through the sensor, and then the pressing operation of the pressing roller is controlled according to the pressing displacement value.

As a preferred solution of the present invention, a first pressure sensor is provided in the first pressing cylinder 41; the upper driving roller 11 presses down the segment of the slab through the pressure value obtained by the first pressure sensor; and/ Or, a second pressure sensor is provided in the second pressing cylinder 42 ; the upper free roller 21 presses down the segment of the billet through the pressure value acquired by the second pressure sensor. The control of the pressing process of the pressing roller can also be completed by setting the size of the pressure value. A pressure sensor and a displacement sensor can be installed in the depression cylinder at the same time, so as to realize the dual control mode of pressure and displacement.

As a preferred solution of the present invention, the distance between adjacent driving rollers 1 and free rollers 2 is 430-480 mm. A small distance can effectively avoid the appearance of bulging.

The present invention provides a method for large reduction of a segment of a slab, using the device for large reduction of a segment of a slab to perform large reduction of a segment of a slab, comprising the following steps:

S1. According to the interval position of the slab solid phase ratio of 0.3 to 0.8, determine the casting resistance of the large reduction device of the sector section of the slab when it is under large reduction;

S2. Determine the initial value of the transmission device according to the casting resistance, and complete the large reduction of the segment of the slab; wherein, when the reduction rollers for the large reduction of the segment of the slab are any pair of driving rollers, The transmission device connected by the remaining driving rollers together provides pressure for the drawing resistance, and the free rollers that have not been subjected to large reduction are used to press the billet by hot billet; When the lower roll is a free roll, the transmission device connected to the drive roll together provides pressure for the drawing resistance.

The sector of the invention employs at least two pairs of drive rollers 1 . When implementing the reduction, only one pair of the reduction rollers is used for maximum reduction. According to the change of the solid phase ratio in the center of the slab, when the driving roll 1 or the free roll 2 is used to implement single-roll reduction, the other driving roll 1 will give a corresponding pressure to provide a sufficient driving force to avoid the phenomenon of slug stagnation .

As a preferred solution of the present invention, the formula for calculating the drawing resistance of the slab segment large-reduction device under large-reduction is: F=2σδ(2Rh-h ² )/R;

Among them, σ is the average deformation resistance, δ is the thickness of the slab; R is the radius of the reduction roller; h is half of the reduction, and F is the casting resistance generated by a pair of reduction rollers.

The following examples will further illustrate the present invention, so that those skilled in the art can better understand the advantages and features of the present invention.

Example 1

As shown in Fig. 1-Fig. 3, the diameters of driving roll 1 and free roll 2 are 400-450 mm, and the structural type of segmented roll is adopted. The effect is better. Each pair of pressing rollers can implement a pressing force of 200 to 300 tons. Each pair of pressing rollers has two pressing cylinders. Each pair of pressing rollers can be individually pressed by displacement control or pressure control. A displacement sensor is installed in the pressing cylinder, and a proportional valve is used to control the synchronization and position of the oil cylinders on both sides, and the roll gap of the large pressing roll is controlled to implement a large pressing on the slab. Both the upper and lower chambers of the depressing cylinder are equipped with pressure sensors, and the depressing cylinder can implement pressure control through the proportional valve of the hydraulic system. Three pairs of transmission devices 3 are arranged on the sector section.

In the continuous casting project, according to the thickness and steel type of the slab, the slab solidification model calculates the solidification process of the slab based on factors such as molten steel conditions, mold water volume, and secondary cooling water volume. In the range of 0.3-0.8 solid phase ratio in the center of the slab, a pair of reduction rollers adopts displacement control to implement a large reduction of 10-15mm on the slab. Other free rollers 2 that do not implement pressing down adopt less hot billet pressure to press down to prevent belly bulging. The other driving rollers 1 calculate the casting resistance generated according to whether the roller with the large reduction is equipped with the transmission device 3, the reduction amount, the thickness of the slab, etc., and then use a certain pressure to obtain the corresponding friction. Force to provide a large enough driving force to help pull the billet.

This large reduction segment uses five independently controlled large reduction rollers. When the casting slab is not completely solidified, a small pressure can be used to implement a large reduction of 10-15mm on the casting slab to ensure that the center of the casting slab is loose. improvement effect. The roller spacing is small, so that the fan section has a larger range of pulling speed adaptation without the problem of belly bulging. Adopting three pairs of drive rollers 1 can ensure that the sector section can provide a sufficient driving force regardless of whether the rollers that implement a large reduction are equipped with a transmission device 3 or not.

It can be seen from the above-mentioned specific embodiments that in the device and method for large reduction of a slab sector provided by the present invention, at least two pairs of driving rollers and free rollers arranged between adjacent driving rollers are arranged in the sector, and, Each pair of pressing rollers is separately provided with pressing cylinders, so that each pair of pressing rollers can be individually pressed. Since multiple pairs of pressing rollers work together, the roll diameter of the individual pressing rollers can be reduced. The roll distance between the adjacent rolling rolls is small, which effectively avoids the appearance of bulging, and the rolling can be carried out within the range of the solid phase ratio. Since the slab is not fully solidified, the required rolling force is small, which reduces the impact on the Rigidity requirements of the frame of the sector section; different from the conventional sector section with only one pair of drive rollers, the present invention uses at least two pairs of drive rollers, and only one pair According to the change of the solid phase ratio in the center of the slab, when the driving roller or free roller is used to implement single-roll reduction, the other driving rollers will give corresponding pressure to provide sufficient driving force, effectively Avoid the phenomenon of stagnation.

The device and method for large segment reduction of a slab according to the present invention are described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various improvements can be made without departing from the content of the present invention to the above-mentioned device and method for large sector segment reduction of slab proposed in the present invention. Therefore, the protection scope of the present invention should be determined by the contents of the appended claims.

Claims (10)

1. A device for large depressing of a segment of a slab, comprising: a pressing roller and a pressing control device; wherein,,

the pressing roller comprises at least two pairs of driving rollers and a pair of free rollers arranged between the adjacent driving rollers; each pair of driving rollers comprises an upper driving roller and a lower driving roller, and each pair of free rollers comprises an upper free roller and a lower free roller;

each pair of driving rollers is connected with a transmission device, and the upper driving rollers and the lower driving rollers are driven to rotate through the transmission device;

the pressing control device comprises a first pressing cylinder arranged on the upper driving roller and a second pressing cylinder arranged on the upper free roller.

2. The slab sector high-pressure reduction device according to claim 1, wherein,

the pressing roller includes three pairs of driving rollers and two pairs of free rollers.

3. The slab sector high-pressure reduction device according to claim 1, wherein,

the roller diameter of the driving roller is 400-450 mm; and/or the number of the groups of groups,

the roller diameter of the free roller is 400-450 mm.

4. The slab sector high-pressure reduction device according to claim 1, wherein,

the pressure values of the driving roller and the free roller are 200-300 tons.

5. The slab sector high-pressure reduction device according to claim 1, wherein,

the first pressing cylinders are arranged at two ends of each pair of driving rollers; and/or the number of the groups of groups,

the second pressing cylinders are arranged at two ends of each pair of free rollers.

6. The slab sector high-pressure reduction device according to claim 1, wherein,

a first displacement sensor is arranged in the first pressing cylinder; the upper driving roller presses down the sector section of the casting blank through the moving displacement value obtained by the first displacement sensor; and/or the number of the groups of groups,

a second displacement sensor is arranged in the second pressing cylinder; and the upper free roller applies pressing to the fan-shaped section of the casting blank through the moving displacement value obtained by the second displacement sensor.

7. The slab sector high-pressure reduction device according to claim 1 or 6, characterized in that,

a first pressure sensor is arranged in the first pressing cylinder; the upper driving roller presses down the fan-shaped section of the casting blank through the pressure value obtained by the first pressure sensor; and/or the number of the groups of groups,

a second pressure sensor is arranged in the second pressing cylinder; and the upper free roller applies reduction to the fan-shaped section of the casting blank through the pressure value obtained by the second position pressure sensor.

8. The slab sector high-pressure reduction device according to claim 1, wherein,

the distance between the adjacent driving roller and the free roller is 430-480 mm.

9. A method for large-pressing a segment of a slab, characterized in that the segment of the slab is large-pressed by the segment large-pressing device of the slab according to any one of claims 1 to 8, comprising the steps of:

according to the interval position of the solid phase ratio of the casting blank of 0.3-0.8, determining the blank pulling resistance of the sector section large-reduction device of the slab under large reduction;

determining an initial value of the transmission device according to the blank pulling resistance, and finishing the large depression of the sector section of the plate blank; when the reduction rollers for carrying out large reduction on the sector section of the casting blank are any pair of driving rollers, the transmission devices connected with the remaining driving rollers provide pressure for the blank drawing resistance together, and the free rollers without carrying out large reduction adopt hot blank reduction on the casting blank; when the reduction rolls, which carry out a high reduction on the segment of the cast strand, are free rolls, the drive means connected by the drive rolls together provide pressure for the withdrawal resistance.

10. The method of large depression of a segment of a slab according to claim 9, wherein,

the calculation formula of the blank pulling resistance of the sector section large-pressing device of the slab under large pressing is as follows: f=2σδ (2 Rh-h) ² )/R；

Wherein sigma is average deformation resistance, and delta is thickness of the casting blank; r is the radius of the reduction roller; h is half of the reduction, and F is 1 pair of the resistance to the pulling of the blank by the reduction.

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