JPS59126723A - Hardening device of steel pipe - Google Patents

Abstract

PURPOSE:To cool uniformly a steel pipe over the entire length thereof and to obtain a hardened steel pipe having a good shape by injecting cooling water on the inside and outside surfaces of the steel pipe and transferring the steel pipe in the longitudinal direction. CONSTITUTION:A steel pipe 9 to be hardened is fed longitudinally by a roll table 17. An inside nozzle pipe 5 provided with inside cooling nozzles 7 and self-aligning guide wheels 10 on the outside circumference is held along the table 7 at the approximate center of a cylindrical header 2 with outside cooling nozzles 3. The pipe 9 is guided by the plug 8 of the pipe 5 so as to be held concentrical with the pipe 5, and is supported by the wheels 10. The supporters 6 open successively just after supporting with the wheels and close successively upon passage of the rear end of the pipe 9 thereby supporting the pipe 5. The pipe 9 is cooled by the cooling water from the nozzles 3, 7 during this time, and when the rear end of the pipe 9 passes the range disposed with the nozzles 7, the supply of the cooling water to the pipe 5 is interrupted. An arm 14 is then rotated and raised to pull up a water suction hose 13, etc. to the position where the advance of the pipe 9 is not interfered with.

Description

[Detailed description of the invention] The present invention relates to a steel pipe hardening device.

With the recent expansion of uses for steel pipes, improvements in various properties such as strength, toughness, and crushing strength have become even more desirable. This tendency is particularly strong for seamless steel pipes used in the development of deep-seated oil fields and offshore oil fields. In order to obtain high-grade steel pipes with such excellent properties, methods such as adding alloying elements and heat treatment are used. In particular, heat treatment is widely used because it can save alloying elements and reduce manufacturing costs. There is.

In particular, quenching and tempering have come to be widely used in steel pipes, and have recently been applied to everything from small diameter pipes to large diameter pipes. There are various methods for hardening steel pipes.
Conventionally, external hardening was mainly performed.

Although the external surface hardening method for steel pipes allows for continuous hardening, the cooling rate rapidly decreases as the wall thickness increases, so it is necessary to adjust the hardenability of the material using alloying elements such as Mo depending on the wall thickness. was there.

In response, recent advances have been made in the development of immersion hardening technology, which cools medium and small diameter pipes from the inside and outside of the pipe, and is now able to provide sufficient cooling capacity even for small diameter, thick walled pipes, which are considered to be the most difficult to harden. It has become possible. However, the cooling conditions at the ends of the pipe and the center of the pipe are different, and the shape of the steel pipe after quenching is likely to deteriorate and cause bends.

The present invention was made in order to solve the above-mentioned drawbacks of the prior art, and it provides uniform cooling conditions by injecting cooling water onto the inner and outer surfaces of steel pipes, and also makes it possible to harden thick-walled pipes. In addition, by transferring the steel pipe in the lengthwise direction and uniformly cooling it over the entire length, a hardened steel pipe with a good shape can be obtained. The present invention will be explained below with reference to the drawings.

Fig. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, and Fig. 2 is its A-A
The enlarged cross-sectional view, Figure 3 is the same < BB enlarged cross-sectional view, Figure 4
The figure is an enlarged sectional view taken along the same line C-C.

In these figures, 1 is an external hardening device, 2 is a cylindrical header of an external cooling nozzle, and 3 is an external cooling nozzle provided on the inner periphery of the cylindrical header 2.

4 is an internal hardening device. Reference numeral 5 denotes an inner nozzle pipe, which is held approximately at the center of the cylindrical header 2 by supports 6a to 6d installed at several locations along its length. As shown in the cross-sectional views of FIGS. 1 and 2, around the inner nozzle pipe 5, inner cooling nozzles 7 are provided in the section where the outer nozzles 3 are provided in the length direction of the pipe.

A plug 8 is provided at the tip of the nozzle pipe 5 to prevent the internal cooling water from flowing upstream in the line direction without interfering with passage of the steel pipe to be hardened. In addition, at several locations in the length direction of the nozzle pipe 5, as shown in the cross-sectional views of FIGS. A core guide wheel 10 is provided. Further, a cooling water supply port 11 is provided at the rear end of the nozzle pipe 5, and a water supply hose 13 having a cap 12 that fits therein is supported by a swinging arm 14. The water supply port 11 and the water supply hose fitting 12 are configured to be attached and detached according to the push/pull operation of the water supply port 15.

A solenoid valve 16 is provided at one end of the water supply hose to supply and stop the cooling water.

Note that the distance between the first supporter 6a and the last supporter 6d is slightly longer than the length of the steel pipe 9 to be hardened. Further, 17 is a roller table for conveying the steel pipe 9 to be hardened;
8 is a pinch roll.

Next, the operation of the embodiment of the present invention configured as described above will be explained. In FIG. 1, the inner nozzle nozzle (eve 5) is held approximately at the center of the cylindrical header 2 of the outer nozzle by supports 6a to 6d.Now, when the steel pipe 9 to be hardened is fed by the roller table 17, the plug 8 6, which is guided by the inner nozzle pipe 5 and becomes concentric with the inner nozzle pipe 5, and then the steel pipe 9
When the steel pipe moves forward, its inner periphery is supported by the guide wheel 10 and becomes concentric with the inner nozzle/cive 5. Immediately after this, the supporter 6a is opened vertically by the hydraulic cylinder 19a, and the steel pipe becomes ready to continue moving forward. Similarly, supporter 6
b to 6d are sequentially opened to advance the steel pipe 9, and then the supports 6 through which the rear end of the steel pipe 9 has passed are sequentially closed to support the inner nozzle pipe 5.

After the rear end of the steel pipe 9 passes through the area where the inner surface cooling nozzle 7 is provided, the electromagnetic valve 16 is operated to shut off the inner surface cooling water. ℃, operate the hydraulic cylinder 15 to rotate and lift the arm 14 to a position where the mouthpiece 12 and water supply hose 13 do not obstruct the forward movement of the steel pipe. The steel pipe 9 that has been cooled is then transferred to the front of the apparatus. After that, the supply of inner surface cooling water is started again, and preparations are made to start cooling the next steel pipe to be hardened.

In order to shorten as much as possible the period during which the inner surface cooling water is stopped between the end of cooling the inner surface of the steel pipe 9 and the end of transferring it to the outside of the apparatus, the roller goople 20 on the raised side from the supporter 6b is driven separately from the roller goople 17 on the entry side. Using the system, the steel pipe 9 is transported and unloaded at the maximum speed regardless of the transport speed during quenching. Note that cooling water is always supplied to the outer surface cooling nozzle 3.

As explained above, according to the present invention, cooling water is injected onto both the inner and outer surfaces of the steel pipe to cool the steel pipe while feeding it in the length direction, so that the thick-walled steel pipe can be uniformly cooled and quenched over the entire length. and continuous hardening work is possible.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, and Fig. 2 is its A-A
3 is a sectional view taken along the line BB, and FIG. 4 is a sectional view taken along the line CC. ]... External cooling device, 3... External cooling nozzle,
4. Internal cooling device, 6. Supporter, 7. Internal cooling nozzle, 8 =. Plug, 9. Steel pipe to be hardened, 10. Alignment guide wheel, 11. Water supply port,
14...Arm, j7...Roller table, 18
...vinci roll, 20 roller table, Patent applicant's representative Patent attorney Tomoyuki Yafuki (and 1 other person) Figure 2 Figure 4 Figure 3

Claims (1)

[Claims] An inner nozzle pipe with a refrigerant injection port and an alignment guide wheel arranged on the outer periphery is installed along the conveying device that conveys the steel material to be hardened in the length direction, and the inner nozzle pipe is connected to a fluid pressure cylinder to raise and lower the material. Constructed so that it can be supported with flexible supports,
An outer nozzle for injecting refrigerant is disposed toward the outer periphery of the inner nozzle pipe, and a refrigerant supply hose is disposed near the end of the inner nozzle pipe, and the fitting part of the hose is connected to an advancing/retracting device to connect the inner nozzle pipe to the inner nozzle pipe. A steel pipe quenching device with a removable end and refrigerant supply port.