JPH05331548A - Heat treatment appartus for steel material - Google Patents

Abstract

PURPOSE:To execute cooling treatment to a long size steel material without developing flaw caused by members for restraining on the steel material surface. CONSTITUTION:In a heat treatment apparatus equipped with plural restraining devices 1 for restraining plural positions in the longitudinal direction of the long size steel material and cooling the whole length of the steel material at the same time, follow-up driving device 2 enabling slide-shifting of the restraining devices 1b for restraining at least the parts except the central part in the longitudinal direction of the steel material and slidingly shifted while following up to the shrinkage of the steel material at the time of cooling these restraining devices are arranged so as not to develop the slippage of the material at the restraining parts. Further, in the steel material restraining member constituting the restraining device, coolant supplying mechanisms 13 enabling supply of the coolant on the abutted surface of the steel material are arranged and the coolant is supplied to the steel material part abutted on the steel material restraining member so as to obtain the steel material without uneven hardness in the longitudinal direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus for steel materials such as rails.

[Prior art]

In cooling treatment of steel immediately after rolling,
It is important to strictly control the cooling rate in order to obtain a desired structure and hardness, and in order to obtain the cooling rate as set, it is necessary to keep the relative positional relationship between the material to be heat treated and the cooling nozzle accurate. For this reason, particularly in the cooling treatment of the asymmetric cross-section steel material or the non-uniform cross-section cooling treatment, a method is adopted in which the material to be heat treated is firmly restrained and the positional relationship of the material to be heat treated with respect to the cooling nozzle is accurately maintained.

However, when a long steel material, for example, a rail having a length of 25 m is simultaneously cooled from 800 ° C. to 500 ° C., the rail contracts about 105 mm in the longitudinal direction. Therefore, if a long steel material is cooled while being constrained in the longitudinal direction, the contraction causes the material to slip at the constrained portion, causing a so-called slip flaw on the surface of the material to be heat treated, resulting in a product defect. In order to solve such a problem, Japanese Patent Laid-Open No. 207118/1982 provides a clamp roll that can rotate only in one direction as a device for preventing the occurrence of slip flaws in a restraint portion in a quenching device for a long steel pipe. Restraint devices have been proposed.

[0004]

In this apparatus, the object of heat treatment is a line-symmetrical steel pipe, and it does not bend greatly unless special adverse conditions such as partial cooling are applied. Therefore, the clamp device is not required to have a great rigidity, and the main matter is to be able to cope with the dimensional change in the longitudinal direction, and it is sufficient if the manipulator can exhibit its own mobility. However, the rail has a great degree of asymmetry around the axis, and the heat treatment apparatus must be able to withstand a large bending stress during cooling. For this reason, the heat treatment apparatus needs to have high rigidity, and as a result, it is inevitable that the heat treatment apparatus becomes large-scale, and the weight also increases. Further, also in such a device, it is necessary to be able to exhibit maneuverability without inhibiting expansion and contraction of the cooled rail in the axial direction.
In view of such conventional problems, an object of the present invention is to provide a heat treatment apparatus capable of cooling a long steel material without causing flaws on the surface of the steel material due to a restraining member.

[0005]

The apparatus of the present invention for achieving the above object is provided with a plurality of restraint devices for restraining a long steel material at a plurality of locations in the longitudinal direction, and a heat treatment apparatus for simultaneously cooling the entire length of the steel material. In at least, a restraint device that restrains at least the central portion in the longitudinal direction of the steel product is slidable in the longitudinal direction of the steel product, and has a follow-up drive device that slides the restraint device following the contraction of the steel product during cooling. Is a heat treatment apparatus for steel materials.
Further, the steel material constraining member constituting the restraint device may include a refrigerant supply mechanism capable of supplying a refrigerant to the steel material contact surface.

[0006]

In the state where the steel material is supported at the cooling processing position in the heat treatment apparatus, the steel material is restrained by the steel material restraining member constituting the restraint device. When the entire length of steel in the longitudinal direction is cooled all at once by blowing a refrigerant, the steel shrinks in the longitudinal direction. Then, it slides in the longitudinal direction of the steel material. Therefore, the slippage of the material does not occur at the restraint portion, and the slippage of the steel material due to the restraint member does not occur.

Further, in the device in which the steel material restraining member of the restraint device is provided with the refrigerant supply mechanism capable of supplying the refrigerant to the steel material contact surface, the refrigerant such as air or steam is supplied to the steel material contact surface of the steel material restraining member. Then, the steel material surface with which the steel material constraining member abuts is cooled. The cooling process of the steel material in the device of the present invention is performed by injecting the refrigerant from the refrigerant injection nozzle around the steel material, but the steel material portion in contact with the steel material restraining member is in the heat retaining state because it is covered with the same member, etc. Part and quality (hardness)
May be different. In this respect, in the apparatus in which the steel material restraining member is provided with the refrigerant supply mechanism, the refrigerant hits the steel material portion with which the steel material restraining member abuts, so that a steel material having no hardness unevenness in the longitudinal direction can be obtained.

[0008]

1 and 2 show an embodiment in which the present invention is applied to a rail heat treatment apparatus, and only a restraint device in the heat treatment apparatus is partially shown. As shown in FIG. 1, a plurality of restraint devices 1a and 1b are arranged at appropriate intervals along the longitudinal direction of the heat treatment device, and a long rail A
It is made possible to restrain at a plurality of positions in the longitudinal direction. In this embodiment, a restraint device 1 for restraining the central portion of the rail in the longitudinal direction.
a is a fixed type, and another restraint device 1b is slidable in the longitudinal direction of the steel material by the follow-up drive device.
In this way, the restraint device 1 that restrains the central portion of the rail in the longitudinal direction.
By making a a fixed type, the rail contracts toward the center in the longitudinal direction during cooling. Therefore, the amount of sliding movement of the restraint device 1b associated with contraction can be reduced, and the stroke of the follow-up drive device 7 (cylinder device) described later can be shortened.

FIG. 2 shows the structure of each restraint device 1b. In each restraint device 1b, a slide base 2 slidable in the rail longitudinal direction on a base X, and a rail support portion provided on this slide base 2 are shown. 3 and a slide base 2, which are supported on the slide base 2 so as to be rotatable in a direction transverse to the longitudinal direction of the rail.
It is composed of a pair of clamp arms 4 that clamp both sides of the rail foot portion between and, and a cylinder device 5 for rotating each of the clamp arms 4.

The pair of clamp arms 4 has a shape bent at each intermediate portion in the longitudinal direction, and the tip end portion thereof constitutes a clamp portion 41 for restraining the rail. The clamp arm 4 is arranged on the slide base 2 so as to face each other with the rail supporting position sandwiched therebetween, and is pivotally supported 6 through the bent portion so as to be vertically rotatable. The pair of clamp arms 4 clamp the foot portions on both sides of the rail between the clamp portion 41 and the rail support portion 3. The cylinder device 5
Has its main body supported on the slide base 2, and its operating rod 51 is connected to the rear end of the clamp arm 4.

Each restraint device 1b having such a structure can be moved in the longitudinal direction of the rail by sliding the slide base 2 on the base X. Further, a follow-up drive device 7 is attached to each restraint device 1b for moving the device in the longitudinal direction of the rail track following the contraction of the rail track. The follow-up drive device 7 is composed of a cylinder device, and an operating rod 71 of the cylinder device is connected to the slide base 2. In the figure, a is a follow-up control device, b is a drive unit of a follow-up drive device, and the follow-up control device a is a drive unit b based on the amount of contraction of the railroad obtained from the material, length, temperature, etc. of the steel material.
The stroke of the follow-up drive device 7 is controlled via.

On the other hand, the restraint device 1a for restraining the central portion in the longitudinal direction of the rail is the same as the restraint device 1b described above except that the clamp arm 4 and the cylinder device 5 have the same structure.
It is not movable like b, but is fixed and fixed on the base. In some cases, the restraint device 1a that restrains the central portion in the longitudinal direction of the rail may be configured to be slidable in the longitudinal direction of the rail as in the restraint device 1b.

Further, as shown in FIGS. 3 and 4, in the present embodiment, the clamp portion 41 of the clamp arm 4 constituting the restraint devices 1a and 1b can supply the refrigerant to the rail contact surface thereof. Is provided so that the portion of the rail foot toe which is restrained by the clamp portion 41 can be cooled. That is, the clamp portion 41 that restrains the rail foot portion is formed with a plurality of refrigerant supply holes 8 that open to the rail contact surface 410 of the clamp portion 41. A groove 9 extending from each of the coolant supply holes 8 in a plurality of directions is formed. In this embodiment, the grooves 9 are formed in a grid on the rail contact surface 410, and the openings of the coolant supply holes 8 are located at the intersections of the grooves 9. The coolant is supplied to each coolant supply hole 8 through a supply pipe (not shown). In addition, in other drawings, 13 is a refrigerant injection header for injecting a refrigerant on a rail.

According to such an apparatus, the rail A is loaded into the heat treatment apparatus and is supported on the rail supporting portion 3, and the pair of clamp arms 4 of the respective restraint devices 1a and 1b are connected to the cylinder device. 5, the foot portions on both sides of the rail are clamped between the clamp portion 41 and the rail support portion 3. When the entire length of the rail A in the longitudinal direction is simultaneously cooled, the rail A contracts in the longitudinal direction as shown in FIG. 1, but the restraint device 1b keeps the rail A restrained and follows the contraction of the rail by the follow-up drive device 7. Slides in the longitudinal direction of the rail. Therefore, the material does not slip at the clamp portion 41,
There is no occurrence of slippage defects at the foot of the rail due to the clamp arm 4, which is a restraining member.

Refrigerant (air, steam, etc.) is supplied to the refrigerant supply hole 8 of each clamp portion 41 through a supply pipe, and this refrigerant flows along the groove 9 to contact the clamp foot 41. Cool the constrained part at the tip.
As a result, the entire length in the longitudinal direction of the rail can be uniformly cooled without causing uneven cooling. When the cooling process is completed, the clamp arm 4 is opened, the rail A is carried out of the heat treatment apparatus, and then each restraint device 4 that slides following the contraction of the rail is driven by the follow-up drive device 7, and the cooling process is performed. Move / return to the previous original position.

FIG. 5 to FIG. 7 show a more specific embodiment when the present invention is applied to a rail heat treatment apparatus. This rail heat treatment apparatus includes a transport device 10 for transporting a rail in a rail extension direction, a cooling device 11 provided in parallel with the transport device, and a rail between the transport device 10 and the cooling device 11 while rolling the rail. It is composed of a plurality of turning / transporting devices 12 for transporting.

The cooling device 11 is provided with a plurality of refrigerant jet headers 13a and 13b for cooling the rail head top portion and the rail head side portion which can be moved up and down, and a plurality of the above-mentioned cooling head headers which are provided at appropriate intervals in the longitudinal direction of the device. The restraint device 1 is composed of a refrigerant injection header 13c for cooling the bottom of the rail, which is arranged below the rail supporting position. Each of the refrigerant injection headers 13a, 13b, 13c has a refrigerant injection nozzle. A pedestal 14 is provided above the cooling device 13, and an elevating frame 16 is held on the pedestal 14 via an elevating device 15 (cylinder device) so as to be vertically movable. The refrigerant jet headers 13 a and 13 b for cooling the rail head top portion and the rail head side portion are mounted and fixed to the elevating frame 16.

Each of the restraint devices 1 has the structure shown in FIG. 2, and is provided at four positions (generally, in the longitudinal direction of the cooling device).
They are arranged at intervals of about 1.5 to 5 m). In this embodiment, since there is no restraint device for restraining the longitudinal central portion of the steel material, any restraint device 1 is slidable in the longitudinal direction of the rail as shown in FIG. Similar to the embodiment shown in FIG. 1, a restraint device for restraining the central portion in the longitudinal direction of the rail may be provided, and the restraint device may be fixed. The base X that supports each restraint device 1 is provided on a support frame 17 arranged at the bottom of the device. This support frame 1
Reference numeral 7 constitutes an oscillation mechanism 18, which will be described later, and is configured so that it can be moved back and forth in the machine longitudinal direction by a traveling roller 20 rolling on a rail 19.

The refrigerant injection header 13c for cooling the bottom of the rail is arranged below the rail supporting position of the restraint device 1, and has a discontinuous portion in the arrangement portion of each rolling / conveying device 12. The carrying device 10 is a device for carrying the rail in the extending direction thereof, and is arranged laterally of the cooling device 11 in parallel therewith. The carrying device 10 has a plurality of table rollers 21.

The turning / conveying device 12 has a holding body 22 having a receiving surface 220 having an L-shaped cross section for holding a rail. In this embodiment, it is between the conveying device 10 and the cooling device 11. Are provided at appropriate intervals in three places. Figure 7
Shows a specific structure of the turning / transporting device 12. The turning / transporting device 12 includes a lift table 24 that can be lifted and lowered by a lifter 23, and the transfer device 10 with respect to the lifting table 24.
And a trolley 25 movably provided between the cooling device 11 and
A cylinder device 26 for driving the carriage 25;
The holding body 22 is rotatably pivoted 27 at the tip of the carriage 25, and a cylinder device 28 that rotationally drives the holding body 22. In the figure, 2
Reference numeral 9 denotes a traveling roller of the carriage, 260 denotes an operating rod of the cylinder device 26, and 280 denotes an operating rod of the cylinder device 28.

According to such a device, the carriage can be conveyed by moving the carriage 25 while the rail is held by the receiving surface 220 of the holder 22, and the cylinder device 28 is operated to operate the holder. By rotating 22 about 90 °, the rail held on the receiving surface 220 is rotated about 90 °,
That is, it can be freely rotated between the upright posture and the horizontal posture. In order to avoid interference with the table roller 21 and the restraint device 1, the holding body 22 moves along a locus indicated by a broken line x in FIG. 5 by moving the lifter 24 up and down by the lifter 23 and moving the carriage 25. Then, carry in and out the rail A.

Further, in this embodiment, there is provided an oscillation mechanism 18 for oscillating the restraint device 1 in the longitudinal direction of the rail. For example, Japanese Patent Publication No. 13012
In the conventional heat treatment apparatus as disclosed in Japanese Patent Publication No. JP-A-2003-242242, a part of the bottom of the rail is always covered by the transfer, which is a loading type transfer device. There is a problem that speed cannot be obtained.
As a result of such a portion having a low cooling rate, there is a drawback that the quality of the foot sole portion becomes uneven.

Therefore, in the present embodiment, the restraint device 1 is oscillated (reciprocated) in the longitudinal direction of the rail by the oscillation mechanism 18 to cool the bottom of the rail at a uniform cooling rate, and This is to ensure uniform quality. The oscillation mechanism 18 includes the support frame 17 that is movable in the device longitudinal direction and a cylinder device 30 in which an operating rod is connected to one end of the support frame 17, and the support device 17 is supported by the cylinder device 30.
The restraint device 1 can be oscillated in the longitudinal direction of the rail by reciprocating in the longitudinal direction of the device.

In this embodiment, the restraint device 1 for restraining the rail is made to oscillate in the longitudinal direction of the rail. However, in some cases, the refrigerant injection header 13c for cooling the sole of the rail is oscillated in the longitudinal direction of the rail. It may have a structure that allows it. In addition, in this embodiment, the refrigerant jet header 13a for cooling the rail head portion and the refrigerant jet header 13b for cooling the rail head side portion are integrally moved up and down via the elevating frame 16, but in some cases, It is also possible to attach both the refrigerant injection headers to different elevating frames and to raise and lower them separately.

In the other drawings, 31 is a supply pipe for supplying a refrigerant such as air to each refrigerant injection header, 32 is a flow rate adjusting valve provided in these supply pipes, and 33 is a supply pipe for supplying refrigerant to each of the supply pipes 31. It is the receiving refrigerant conduit. In addition,
Each of the supply pipes 31 of the refrigerant injection headers 13a and 13b has an expansion tube portion or a flexible tube portion (not shown) in the middle thereof in order to enable the refrigerant injection headers to move up and down.

According to the apparatus of this embodiment as described above, when the transportation apparatus 10 conveys the rail A from the rolling line in the upright posture, the turning / conveying apparatus 12 as shown by the broken line x in FIG. The holder 22 moves to the lower part of the rail A and lifts it upward and conveys it toward the cooling device 11. During this transportation, the holder 22 is moved to about 90
Rotate to rotate the rail A to the upright posture as shown by the phantom line in FIG. The turning / conveying device 12 conveys the rail A to directly above the refrigerant injection header 13c and lowers it to the rail supporting position.

In this state, the clamp arm 4 which is in the open state of the restraint device 1 is operated to restrain both toes of the rail by the clamp portion 41 as shown in FIG. Next, the holding body 22 is retracted to the outside of the cooling device, and the elevating device 15 lowers the refrigerant jet headers 13a and 13b for cooling the rail head top portion and the rail head side portion to be positioned at the cooling processing position. Refrigerant injection header 13a, 13
Refrigerant such as air is jetted from the nozzles b and 13c to each part of the rail A to cool the rail. Then, each restraint device 1 that restrains the rail A slides in the longitudinal direction of the rail by following the contraction of the rail A due to cooling by the follow-up drive device 7. Further, during the cooling, the support frame 17 is reciprocated in the longitudinal direction of the rail by the cylinder device 30, so that the restraint device 1 and the rail A restrained by the restraint device 1 are oscillated in the longitudinal direction. By such oscillation, the entire sole of the rail can be cooled at a uniform cooling rate.

The predetermined cooling rate required for heat treatment of the rail head is set by the rail head and each refrigerant injection header 13
It is carried out by adjusting the distance between a and 13b and the amount of refrigerant injected from each refrigerant injection header. The distance between the rail head and each refrigerant injection header is adjusted by adjusting the height of the elevating frame 16 and the like, and the refrigerant injection amount is adjusted by the flow rate adjusting valve 32 provided in each supply pipe 31.

Also, with respect to the refrigerant injection header 13c for cooling the sole of the rail, the refrigerant injection amount is adjusted by the flow rate adjusting valve 32 of the supply pipe 31. Cooling of the bottom of the rail
In order to minimize the bending amount of the rail, the balance with cooling of the rail head is taken into consideration. During cooling of the rail, the temperature of the top of the rail is detected by a temperature detector (not shown) provided above the rail, and the flow rate adjusting valve 32 is closed when the rail is cooled to a predetermined temperature based on this temperature detection. To stop cooling.

After completion of such cooling treatment, the holder 3 is again provided.
2 into the cooling device 8 and the rail 22 is moved by the holder 22.
Of the restraint device 1, and then the clamp arm 4 of the restraint device 1 is opened, and the rail A is lifted by the holding body 22.
Is transported to the transport device 10 side while being turned to a horizontal posture.
In this example, the carrying device 10 carries in and carries out the rails before and after the cooling treatment, but in some cases, a carrying device dedicated to carrying out is provided on the opposite side of the cooling device 11 so that the rails after the cooling treatment are provided. May be transferred to the transfer device side dedicated to this unloading.

[0031]

As described above, according to the device of the present invention,
When steel materials such as rails contract in the longitudinal direction during cooling, the restraint device slides in the longitudinal direction of the rails following the contraction of the rails while restraining the steel material. Therefore, it is possible to properly prevent the occurrence of slipping flaws.In addition, since the restraining roller turns in a direction that traverses the longitudinal direction of the steel material, when the target of treatment is a rail, the restraining roller is orthogonal to the surface of the foot of the rail. Since they are brought into and out of contact with each other, they do not slip on the surface of the foot of the rail. Therefore, a long steel material can be cooled without causing surface defects due to the restraining member. Further, in the device in which the steel material restraining member is provided with the refrigerant supply mechanism, the refrigerant also hits the steel material portion with which the steel material restraining member abuts, so that the entire length in the longitudinal direction of the steel material is cooled at a uniform cooling rate, and there is no unevenness in hardness in the longitudinal direction. Steel materials can be obtained.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the device of the present invention.

FIG. 2 is a view taken along the line II-II in FIG.

FIG. 3 is a front view partially showing a clamp portion of a clamp arm and a coolant supply mechanism provided therein.

FIG. 4 is a view taken along the line III-III in FIG.

FIG. 5 is a front view showing an embodiment in which the present invention is applied to a rail heat treatment apparatus.

6 is a plan view of the device shown in FIG.

FIG. 7 is a front view showing a turning / conveying device of the device shown in FIG.

[Explanation of symbols]

1, 1a, 1b ... Restraint device, 2 ... Slide base, 3 ... Rail support part, 4 ... Clamp arm, 5 ... Cylinder device, 7 ...
Tracking drive device, 8 ... Refrigerant supply hole, 9 ... Groove, 41 ... Clamping part, a ... Tracking control device

Front page continuation (72) Inventor Kenichi Sakai 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd.

Claims (2)

[Claims] 1. A heat treatment apparatus for simultaneously cooling the entire length of a steel product, comprising a plurality of restraint devices for restraining a long steel material at a plurality of locations in the longitudinal direction, wherein the restraint device for restraining at least a central portion in the longitudinal direction of the steel material A heat treatment apparatus for steel products, which has a follow-up drive device that is slidable in any direction and that slides these restraint devices by following the contraction of the steel product during cooling. 2. The heat treatment apparatus for a steel product according to claim 1, wherein the steel product restraining member constituting the restraint device has a coolant supply mechanism capable of supplying a coolant to the steel product contact surface.