JPS60245719A - Method and device for cooling long-sized steel material having circular section - Google Patents

Abstract

PURPOSE:To suppress deformation such as bending which may arise in cooling by cooling a long-sized steel material to be cooled while rotating the material around the axial center thereof during the transverse feed thereof and restraining the long-sized steel material in the radial direction. CONSTITUTION:The heated long-sized steel material 20 having a circular cross section is fed in the axial direction by feed-in rollers 21 and the position in the axial direction is determined at the terminal end thereof. Walking beams 24 ascend while clampers 29 thereof are held open. The steel material 20 on the rollers 21 are scooped up by the 1st row of rotating mechanism 28 at the walking beams 24. Hydraulic cylinders 34, 36 at the beams 24 are simultaneously operated and the arms 31a, b are erected to restrain the material 20. The material 20 is restrained in the radial direction by the clampers 29 and is cooled in this state by the cooling medium from nozzles 47 while the steel material is rotated around the axial center by rotation driving rollers 30.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for cooling long steel materials having a circular cross section, such as steel pipes and steel bars, and an apparatus for carrying out the method.

Conventional technology Various steel materials are usually subjected to heat treatment after the rolling process and before they are made into products, in order to improve their quality and correct weaknesses during manufacturing. As the environment in which steel is used becomes more severe, the production volume of so-called tempered steel materials that have undergone heat treatment such as quenching and tempering to improve strength and toughness is increasing. This tendency is particularly noticeable in oil country steel pipes used in oil and gas wells, and the production ratio of high-grade steel pipes that are hot-rolled or reheated after rolling and cooling, as well as quenched and tempered, is increasing.

By the way, when a long steel material such as a steel pipe is cooled from a high temperature state for heat treatment, the ratio of length to cross-sectional area is large, so deformation such as bending is likely to occur, resulting in a large amount of deformation in the subsequent process. Straightening is required, and as a result of straightening, there is a high risk of deterioration of the material. Furthermore, cooling of long steel materials such as steel pipes is not limited to rapid cooling for quenching, but may also be performed at a cooling rate that is intermediate between natural cooling and rapid cooling. Even in the case of controlled cooling in which the cooling rate is controlled to , the change in shape is large and the time required for cooling becomes long, and as a result, there is a high risk that cooling efficiency, that is, productivity will decrease. Therefore, when cooling a high-temperature long steel material, it is desirable to pay special attention to preventing bending and improving productivity.

A method for cooling a long steel material having the above-mentioned disadvantageous characteristics,
Conventionally, various methods shown in FIGS. 1 to 3 have been proposed. That is, in the method shown in FIG. 1, a steel material 1 to be cooled, such as a steel pipe, is conveyed vertically in the axial direction by conveying rollers 2 arranged in a row, and the steel material 1 is transported by a cooling device 3 disposed halfway between the conveying rollers 2. This is a method of cooling during transportation. In the method shown in FIG. 1, the cooling force of each part of the steel material 1 in the circumferential direction is increased by changing the axis angle of the conveying roller
Ill turn by reducing the speed difference. Although the degree can be reduced, since the entire steel material 1 is gradually cooled as it is longitudinally fed, it is unavoidable that differences occur in the cooling rate of each portion in the axial direction.

Furthermore, since the method shown in FIG. 1 is a method in which the copper material 1 is cooled while being conveyed vertically, it has the disadvantage that the equipment required for carrying out the method is very long.

For example, outer diameter 114.3 IIllll11 wall thickness 6.35
+un, processing speed of 20 tons per hour for 30 m long pipe material,
When performing controlled cooling at a cooling rate of 800 to 500°C at an average rate of 1°C per second, 98.6+n equipment is required, making the entire equipment so long as to lack practicality.

Further, in the method shown in FIG. 2, the steel material 1 to be cooled that has been vertically fed to the terminal end of the carry-in roller 4 is fed horizontally to a cooling device 6 disposed between it and the carry-out roller 5, and is cooled there.
This is a method in which the paper is vertically conveyed to a predetermined location using a carry-out roller 5. In this method, since the entire steel material 1 is fed into the cooling device 6 at the same time, there is no difference in cooling rate in the axial direction. can be kept extremely small. However, the method shown in FIG. 2 has disadvantages in that the cooling efficiency is poor and the equipment required for implementation is large. For example, when cooling the aforementioned steel material 1 with a length of 30 m,
The method shown in FIG. 2 generally provides a processing speed of only 0.2 kneading degrees per minute. Since this corresponds to a processing speed of 6.1 tons per hour, if a processing speed of 20 tons per hour is to be obtained as described above, the equipment must be capable of cooling at four times the amount of water, which is impractical.

As described above, the method shown in FIG. 1 or 2 has a drawback in either changing the shape of the steel material 1 or increasing the size of the equipment. On the other hand, the method shown in FIG. 3 is a method in which two or several steel materials 1 are cooled simultaneously. That is, two rows of carry-in rollers 7 and two lines of carry-out rollers 8 are arranged, and a cooling device @9 is provided between them, and the two high-temperature steel materials 1 on the carry-in rollers 7 are grabbed by the transfer device 10. At the same time, the steel material 1 is placed on the rotating roller 11 in the cooling device 9. The steel material 1 is rotated about its axis by a rotary roller 11, and in this state, a cooling medium is injected from a nozzle 12 toward the steel material 1. The two steel materials 1 cooled in this way are re-FJed by the transfer equipment [10].
! Lift it up and transfer it to the unloading roller 8. With such a method, the entire copper material 1 can be cooled uniformly, and the processing efficiency can be improved to some extent. However, since the method shown in FIG. 13 is a method of handling two or more steel materials 1 at the same time, it has the disadvantage that special equipment is required.

In other words, the mechanism for extracting the steel material 1 from the heating device in the previous process, the transfer device 10, and the rotating roller 11 must be configured to be able to simultaneously extract and rotate a plurality of steel materials 1. However, since ordinary heat treatment lines, rolling lines, etc. are configured to process and process steel materials one by one, it is almost impossible to incorporate equipment with the above special structure into existing equipment. It cannot be adopted except in special cases such as when building a new factory.

Therefore, the present inventors have already proposed a method for cooling a long steel material in a high temperature state while rotating it at a rotation speed of 60 revolutions per minute or more, and simultaneously transporting it sideways, as a method that can eliminate the above-mentioned drawbacks. Shitaku patent application No. 13867 (Sho 58). According to this method, it is possible to efficiently cool the steel material, and the bending of the steel material can be significantly reduced compared to the above-mentioned method.

However, when higher precision is required, it is quite difficult to adjust the nozzle arrangement and cooling medium injection conditions to achieve a precise cooling rate due to the constant horizontal movement of the steel material. There were times when it was not possible to achieve sufficient accuracy to meet the requirements, and there was still room for improvement.

Problems to be Solved by the Invention As described above, the conventionally known methods have problems in either the shape of the steel material after cooling or the equipment for implementation, and cannot be put to practical use. Further, although the method already proposed by the present inventors can considerably prevent bending of long steel materials, there is still room for improvement in order to meet more advanced requirements.

Means for Solving the Problems An object of the present invention is to provide a method and apparatus that can further reduce bending of a long steel material with a circular cross section and efficiently cool it. In order to transversely feed a long steel material while cooling it, the long steel material is restrained in the radial direction at multiple points in the axial direction, and while the long steel material is being restrained, it is cooled while being rotated about its axis. A method of cooling by applying a medium was adopted. In addition, in order to carry out the above method, the device of the present invention includes clampers that restrain the long steel material to be cooled at multiple locations in the axial direction thereof, which are attached to a conveying device that transports the long steel material horizontally, and the clampers are also restrained. The clamper is equipped with a rotation mechanism that rotates the long steel material around its axis while the long steel material is being fed horizontally, and a nozzle is provided for supplying a cooling medium to the long steel material that is being roughly conveyed horizontally. It is something that can be earned.

Effect: Therefore, according to the method and apparatus of the present invention, by cooling a long steel material with a circular cross section while rotating and transversely feeding it, the cooling rate can be uniformized to a considerable extent over the entire body, and in addition, the cooling rate can be uniformized to a considerable extent over the entire length. Since the parts are restrained in the radial direction, bending of the steel material due to cooling is extremely effectively suppressed.

Embodiment First, an embodiment of the apparatus of the present invention will be described with reference to FIGS. 4 and 5.

FIG. 4 is a layout diagram of a cooling device according to the present invention, and the device shown here cools a steel pipe 20 and is arranged between the terminal end of a carry-in roller 21 and a carry-out roller 22 parallel thereto. This is what I did. That is, a plurality of fixed beams 23 are arranged parallel to each other between the carry-in roller 21 and the carry-out roller 22, and these fixed beams 23 are arranged parallel to each other.
3, a walking beam 24 is disposed as a conveying device for transversely feeding the steel pipe 20.

The walking beam 24 is configured to move in a circular motion while maintaining a horizontal state, similar to the one normally used, and its both ends are connected to the same beam provided on the carry-in roller 21 side and the carry-out roller 22 side, respectively. It is connected to the height support column 25 via a rotary lever 26, and one rotary lever 2
6 is rotated by a drive device 27 such as a motor, so as to move circularly between a position lower than the fixed beam 23 and a position higher than the fixed beam 23.

Each of the walking beams 24 is provided with a plurality of rotation mechanisms 28 for mounting and rotating the steel pipe 2°, and a plurality of clampers 29 for restraining the steel pipe 20 in the radial direction thereof, at regular intervals. There is. Each rotating mechanism 28, as shown in FIG.
and a drive device that rotates it in the same direction. The clamper 29 is composed of a pair of arms 31a and 31b that press down the steel pipe 2o on the rotary drive roller 30 from diagonally above the left and right sides of the steel pipe 2o.
Pinch rolls 32 are attached to the tips of the tubes a and 31b to rotatably press the M tube 20. Each arm 31a, 31b is rotatably attached to the walking beam 24 by a pin, and among the six pairs of arms 31a, 31b, for example, the arm 31a on the right side in FIG. The lower end is rotatably connected to a single rod 33, and the rod 33 is connected to a fifth
By advancing and retreating in the axial direction using the hydraulic cylinder 34 at the left end in the figure, the device is configured to be tilted and erected into each state shown by solid lines and chain lines in FIG. The same applies to the other arm 31b, and the lower end of these arms 31b is rotatably connected to another rod 35.
By moving the rod 35 back and forth in the axial direction by the hydraulic cylinder 36 at the right end in FIG.
The walking beam 24 is configured to be tilted and erected in each state shown by the solid line and the chain line in FIG.
A plurality of rotating machines 4137 and a clamper 3 similar to those in
8 are provided at regular intervals. That is, the rotation 11m37 is for rotating the #ll tube 20, and includes a rotary drive row 539 arranged with its axis directed in a direction perpendicular to the fixed beam 23, and a drive device for rotating it in the same direction. It is composed of. Each clamper 38 presses down the steel pipe 20 on the rotation mechanism 37 from diagonally above on the left and right sides, and has a pinch roller 40 at its tip and is rotatably attached to the fixed beam 23 via a pin. It is composed of a pair of arms 41a and 41b. And these arms 41a, 41
b are tilted and erected by rods 42, 43 and hydraulic cylinders 44, 45 provided correspondingly to each other to hold down or release the steel pipe 20.

Note that the rotation mechanism 37 and clamper 38 on the fixed beam 23 are similar to the rotation mechanism 2 on the walking beam 24.
8 and within the locus of movement of the steel pipe 20 carried by the clamper 29. Therefore, by the walking beam 24 performing circular motion, the steel pipe 20 is intermittently transversely fed from the carry-in roller 21 to the carry-out roller 22 while passing the steel pipe 20 between the fixed beam 23 and the walking beam 24. There is.

Further, above the rotation mechanism 37 in the fixed beam 23, a plurality of nozzles 47 that spray a cooling medium (for example, cooling water) toward the steel pipe 20 are arranged along the moving direction of the steel pipe 20.

Next, a cooling method of the present invention using the above device will be explained.

The steel pipe 2o, which has been heated to a predetermined temperature by the heating device in the previous step, is axially conveyed by the carry-in roller 21,
Its terminal end determines its axial position. The walking beam 24 rises with its clamper 29 opened as shown by the chain line in FIG.
The steel pipe 20 on the top is scooped up by the first row rotation mechanism 28 in the walking beam 24. At almost the same time, each hydraulic cylinder 34, 36 in the walking beam 24 operates, so that each arm 3
1a and 31b stand in the state shown by the solid line in Figure 5, and t
! 4. The pipe 20 is restrained. That is, the steel pipe 20 in a high temperature state is rotated in a predetermined direction about the axis by the rotary drive roller 30 while being restrained in the radial direction by the clamper 29 . Note that the restraint by the clamper 29 is to prevent bending due to cooling, but if the restraining force is too strong, the steel pipe 20 in a high temperature state will be deformed, and if it is too weak, it will not be possible to sufficiently prevent bending. The restraining force is set to the appropriate magnitude by adjusting the pressure in the cylinders 34,36.

When the steel pipe 20 is scooped up from the carry-in rollers 21 as described above, the walking beam 24 is in the ascending process, so the steel pipe 20 moves in an arc as shown by the chain arrow in FIG. It is sent to the rotating machine tank 37 in the first row. In that case, the first row of clampers 38 in the fixed beam 23 are in an open state,
Also, at the same time that the steel @20 is placed on the first row of rotary drive ports 41a and 4Ib of the fixed beam 23, the fixed beam 2
3 clamper 38 is closed and the walking beam 2
4 clamper 29 opens. In this way, the steel pipe 20 is transferred from the walking beam 24 to the fixed beam 23, and is rotated by the rotating flilli 37 while being restrained by the clamper 38 in the fixed beam 23.
It is rotated continuously.

On the other hand, after the king beam 24 reaches the lower limit, it returns to the carry-in roller 2111 and rises, so that the first tube 20 on the fixed beam 23 is moved to the walking beam 24.
At the same time, the Ill tube 20 on the carry-in roller 21 is lifted up by the rotation mechanism 28 in the second row.
Rotation 111 of the first row in the walking beam 24
Scooped up by 1128. To transfer JRR2O3 from the fixed beam 23 to the walking beam 24 as the walking beam 24 rises, open the clamper 29 of the walking beam 24 in advance, and when the walking beam 24 reaches the height of the fixed beam 23, While closing the clamper 29, the fixed beam 23
This is done by opening the clamper 383.

By repeating the above-described operations, the steel pipe 20 is intermittently fed laterally on the fixed beam 23 by the walking beam 24, and finally transferred to the carry-out roller 22.

While being traversed in this manner, the steel pipe 20 passes through a cooling zone by injecting a cooling medium from the nozzle 47, so that the steel pipe 20 is cooled during traversing. In that case, the steel pipe 20 is constantly rotated by the rotating mechanism 28.37 and uniformly cooled over the entirety, and in addition, it is constantly restrained by the clamper 29.38, so that no deformation such as bending occurs. . In addition,
In order to reduce the bending caused by fluctuations in the injection conditions of the cooling medium by the nozzle 47 to a size that can withstand practical use, it is preferable that the rotational speed of the copper tube 20 is set to 60 revolutions per minute or more.

Here, an example of the method of the present invention and a comparative example will be shown.

Example of the present invention A carbon steel 61 tube measuring φ60.3 mm x 4.83 mm x 10 m is heated to 900°C in a heating furnace, rotated while being restrained in the radial direction, and transferred in that state between a walking beam and a fixed beam. It was cooled while being conveyed horizontally.

Comparative Example Cooling was carried out without constraint in the radial direction (2. Cooling was carried out under the same conditions as in the above example).

The results are summarized in Table 1.

Table 1 As is clear from the results shown in Table 1, by increasing the rotation speed of the steel pipe to 60 revolutions per minute or more, the amount of bending per meter can be reduced to 1111 m or less, especially in the radial direction. In the method of the present invention, which applies restraint, the thickness was 0.6 mm or less, which was an improvement of about 30% compared to the comparative method.

Note that when cooling is performed using the device and method described above, the nozzle 4
Since the cooling capacity changes depending on conditions such as the number of nozzles, their jet t, pressure, etc., if the wall thickness of the target steel pipe changes, by appropriately selecting conditions such as the number of nozzles,
The cooling rate can be easily set and maintained at an appropriate rate. In addition, the conditions that affect cooling capacity, such as the number of nozzles, do not need to be uniform throughout the entire body; generally, high cooling capacity is required on the carry-in roller side, so increasing the number of nozzles on the carry-in roller side or It is desirable to increase the number of If you want to further increase the temperature on the delivery roller side, you can form a high-pressure air curtain adjacent to the last row of nozzles and use the air curtain to remove the cooling medium adhering to the outer surface of the steel pipe. It is possible to control the final cooling temperature. Furthermore, there are cases where cooling is required after rapid cooling, and in such a case, a cooling table may be connected to the end of the fixed beam 23 in place of the carry-out roller. In the device described above, the steel pipe 2
Since the cooling conditions are most stable when the steel pipe 20 is placed on the fixed beam 23, the cooling rate can be set with high precision by increasing the amount of steel pipe 20 held and stored on the fixed beam 23. be able to. Furthermore, in the above-mentioned apparatus, since a large number of m-tubes placed on the fixed beam 23 and being transported laterally are cooled at the same time, the processing capacity can be improved by further increasing the number of rotating photographing mechanisms 28, 37. can.

Furthermore, the method and apparatus of the present invention can be applied not only to steel pipes but also to general cooling of long steel materials having a circular cross section, and particularly when applied to the field of seamless steel pipes manufactured by hot rolling, Since it is easy to increase processing capacity, it is suitable for use as a cooling method immediately after rolling.

Effects of the Invention As is clear from the above explanation, according to the cooling method and cooling device of the present invention, the long steel material to be cooled is cooled while being rotated around the axis while being transversely fed, and in that case, the long steel material is cooled while being rotated around the axis. Since the steel sheet is restrained in the radial direction, deformation such as bending due to cooling can be significantly suppressed. In addition, with this invention, it is possible to cool multiple long steel materials at the same time during cross-feeding.
It has good cooling efficiency, in other words, it has excellent practical effects such as being able to perform cooling with small-scale equipment.

[Brief explanation of the drawing]

1 to 3 are schematic illustrations for explaining conventional cooling methods, respectively. FIG. 1 is a layout diagram schematically showing the overall configuration of the device according to the present invention, and FIG. It is a v-v cross-sectional view. 20...Steel pipe, 23...Fixed beat 2, 24...
・Two - king beam, 28.37...rotation mechanism,
29.38... Clamper, 30.39... Rotation drive roller, 31a, 31b, 41a, 41
b-=7-m, 47... nozzle. Figure 1 Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) When transversely feeding a long steel material with a circular cross section that is in a high temperature state while cooling it, the long steel material is restrained in the radial direction at multiple points in the axial direction, and in this restrained state, the axial center is A method for cooling a long steel material with a circular cross section, characterized by cooling the long steel material by applying a cooling medium while rotating the material. (2) The method for cooling a long steel material with a circular cross section according to claim 1, wherein the rotational speed of the long steel material in a restrained state is 60 revolutions per minute or more. (3) A plurality of clampers for radially restraining a long steel material with a circular cross section to be cooled at a plurality of locations in the axial direction are included in the conveying device for transversely transporting the long steel material, and A rotation IIm is provided to rotate the long steel material around its axis in a restrained state, and a plurality of nozzles that supply a cooling medium to the long steel material during lateral transport by the conveying device are provided. A cooling device for long steel materials with a circular cross section, characterized in that the devices are arranged along the feeding direction.