JPH08932B2 - Position control method for heat treatment equipment for ERW pipe seam welds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention follows the displacement of the position of the seam welded portion during the heat treatment of the continuously welded seam welded portion of the electric resistance welded pipe subsequent to welding. The present invention relates to a position control method for correcting the position of a downstream inductor for tempering and the like.

B. SUMMARY OF THE INVENTION The present invention is to perform electric resistance welding when starting a heat treatment work in which a seam welded portion of a continuously welded electric resistance welded pipe is heated and then rapidly cooled after welding, and then reheated such as tempering. If the position of the seam weld is displaced in the circumferential direction of the ERW pipe due to the twist of the ERW pipe during transfer from the pipe welding position, move the heat treatment equipment to the proper position facing the seam weld. In the control method, the fluctuation of the position of the seam weld of the electric resistance welded pipe is detected at a position upstream of the quenching position of the seam weld in the direction of transfer of the electric resistance welded pipe, and then the fluctuation of the position of this seam weld is detected. The value is processed to calculate the predicted position of fluctuation of the seam weld when the seam weld is transferred downstream of the quenching position in the transfer direction. Detection marks, etc. are downstream from the quenching position The downstream detection means is moved to a position corresponding to the predicted position of fluctuation of the seam welded portion so as to be within the detection range of the downstream position detection means of the seam welded part installed at The downstream inductor for tempering, etc. is controlled to move to the expected waiting position, and then the seam weld position detecting means on the downstream side of the quenching position detects the actual position of the seam weld after quenching. By controlling the movement of the downstream inductor for tempering etc. to the proper heating position facing the seam weld corresponding to the actual position after quenching, in addition to fluctuations such as twist during transfer of the electric resistance welded pipe, seam welding The position of the downstream side inductor for annealing or the like is moved and controlled in response to the secondary change in the position of the seam welded portion caused by the rapid cooling of the portion so that the heat treatment can be properly performed.

C. Conventional technology Generally, in seam welds of ERW pipes, the metal of the seam is deteriorated by welding, the mechanical strength is deteriorated, and it is partially hardened due to rapid cooling after welding. It is common to anneal (heat treatment to anneal) after welding in order to recover the normal state by welding.

Conventionally, a seam annealer as illustrated in FIG. 3 has been used for this annealing. This is because the material of the electric resistance welded pipe 1 is induction-heated by the induction coil 2 and welded at the welding point B, and then the seam welded portion indicated by the solid line A is three inductors 3, 3, 3 in this example of the seam annealer. Then, induction heating is gradually performed and annealing is performed. However, during annealing, the electric resistance welded pipe 1 continuously transferred from the welding point B is twisted while being transferred to each of the inductors 3, 3, and the position of the seam welded portion A is changed. It may fluctuate in the circumferential direction of the electric resistance welded pipe, and the seam welded portion A may be disengaged from directly below each of the inductors 3, 3, and proper annealing may not be performed.

Therefore, on the side surface of the electric resistance welded pipe 1, near the welding point B, paint or the like is applied by the marking means 4 to give a linear mark C, and this mark C is located on the upstream side of the inductor 3. Detected by the detector 5, compared with the initial position of the mark C when the electric resistance welded pipe 1 is not twisted, the variation value thereof is detected, and a signal of the variation value is sent to a control device (not shown).
Therefore, the mark detector 5 and each inductor 3 for the variation value,
From the proportional relationship with the distance between 3 and 3, each inductor 3,
The calculation processing for calculating the fluctuation predicted position of the seam welded portion A at the installation locations of 3 and 3 is performed, and the inductors 3, 3 and 3 are arranged along the outer circumference of the electric resistance welded pipe 1 in accordance with the fluctuation predicted position. Each was controlled to move to an appropriate position and annealed.

D. Problems to be Solved by the Invention Recently, there has been a growing demand for using alloy steels such as chromium, manganese, and molybdenum as the material of the electric resistance welded pipe 1. In the case of such a material, as a heat treatment for recovering the required properties of the seam welded portion, it is generally heated first, then rapidly cooled, and then heat-treated for tempering or the like. is necessary.

Due to this treatment, the inventor of the present invention sequentially provides two heating inductors 7 as heat treatment equipment at a position downstream of the welding point B of the electric resistance welded pipe 1 in the transfer direction as illustrated in FIG. , 7
Then, a cooling shower 8 for quenching is installed, and then three tempering inductors 9, 9, 9 are installed. Further, a marking unit 4 and a mark detector 5 for detecting the variation value by detecting the mark C are installed, and the tempering process is performed by the control unit which has received the variation value signal as in the prior art. Attempts were made to perform heat treatment by controlling the movement of the working inductors 9, 9, 9 so as to correspond to the predicted fluctuation position of the seam welded portion A.

However, when the seam welded portion A of the electric resistance welded pipe 1 is rapidly cooled by the cooling shower 8, a new twisting deformation occurs in the electric resistance welded pipe 1 from that portion, and for example, one-dot chain lines e and f are shown in FIG.
As shown in FIG. 3, the tempering inductors 9 and 9 are displaced from the initial predicted position (shown by the chain double-dashed line d in the figure) in either the left or right direction along the outer circumference of the electric resistance welded pipe 1. ,
No. 9 was displaced from the actual position of the seam welded portion A, and the problem that proper tempering processing could not be performed occurred.

In view of the above points, the present invention, in the heat treatment of the seam welded portion of the electric resistance welded pipe, by rapidly cooling the seam welded portion,
Even if the seam welded part fluctuates in a new direction from that part, follow this fluctuation so that the downstream inductor for tempering etc. can be smoothly moved and controlled so that heat treatment can be performed properly. With the goal.

E. Means for Solving the Problems The position control method of the heat treatment equipment for seam welded portion of the electric resistance welded pipe of the present invention is such that the welding point of the seam welded portion of the electric resistance welded pipe and cooling at the time of starting the heat treatment work of the seam welded portion of the electric resistance welded pipe. Position fluctuation value of the seam welded portion of the electric resistance welded pipe detected by the upstream side fluctuation detection means of the seam welded portion, which is calculated between the fluctuation predicted position of the seam welded portion. Corresponding to the predicted position, at least the downstream inductor for tempering, etc., and the downstream fluctuation detection means of the seam weld installed downstream of the quenching cooling unit, up to the respective predicted corresponding positions. The movement is controlled, and then the actual position of the seam welded part to which a new position change is added during the rapid cooling is detected by the downstream side fluctuation detection means of the seam welded part, which is installed on the downstream side of the quenching cooling part. , Each tempering corresponding to this detection result Movement control to the downstream side inductor equal to a position opposite to each of the seam weld, is characterized in that so as to perform the heat treatment.

F. Action With the above-mentioned configuration, the seam welded portion placed at least downstream from the cooling portion in response to the fluctuation of the seam welded portion during the transfer of the electric resistance welded pipe from the welding point side. The downstream side fluctuation detecting means and the downstream side inductor for tempering etc. are controlled to move to the fluctuation prediction corresponding position by the upstream side fluctuation detecting means and kept waiting, and when the seam welded part is cooled rapidly. Even if the total amount of fluctuations is increased by newly changing the fluctuations in addition to the initial fluctuations, the fluctuations can be detected without deviating from the detection range of the downstream fluctuation detecting means. Along with this, it is possible to move the downstream inductor, such as for tempering, which has been moved to the fluctuation prediction corresponding position in advance and has been waiting for it, from the basic position directly to the re-fluctuation position where new fluctuation due to rapid cooling is added. On the other hand, there is an effect that the movement is controlled quickly with a short movement distance, the heating is appropriately performed, and the heat treatment such as tempering can be performed.

G. Examples Hereinafter, one example of the position control method of the heat treatment equipment for seam welded portion of the electric resistance welded pipe of the present invention will be described with reference to FIGS. 1 and 2. In FIGS. 1 and 2, parts corresponding to those in FIGS. 3 and 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the figure, reference numeral 1 denotes an electric resistance welded pipe, which is continuously welded at a welding point B by an induction coil 2 to form a seam welded portion A, which is transferred in a direction of an arrow G. Also,
On the downstream side of the welding point B of the electric resistance welded pipe 1 in the transfer direction G,
Sequentially, two upstream inductors 7, 7 for heating which are heat treatment equipment, a cooling shower 8 which is a cooling machine for quenching, and three downstream inductors 9, 9, 9 for tempering etc. are installed. To do.

The upstream inductors 7, 7 for heating and the downstream inductors 9, 9, 9 for tempering and the like are individually and independently shown in FIG. 2 by a controller (not shown). Drive device installed along the outer peripheral direction of ERW pipe 1 as shown
The rotation position adjustment control is possible by using 15.

In addition, marking means 4 is provided near the welding point B of the electric resistance welded pipe 1.
Lined mark C on the side surface of the electric resistance welded pipe 1 which is installed and transferred.
To be written. Further, in this example, in the section between the upstream heating inductor 7 in the transfer direction G and the marking means 4,
An upstream mark detector 5 which is an upstream variation detecting means of the seam welded portion A is installed. Further, the downstream side inductors 9, 9 and 9 for tempering etc. each have a downstream side mark detector 10 which is a downstream side variation detecting means of the seam welded portion A on the inlet side (upstream side) thereof. It is installed integrally, and the rotary position adjustment can be controlled by the same drive device 15 (not shown in FIG. 1) as that shown in FIG. 2 integrally with the downstream inductor 9 for tempering or the like. To configure.

Next, a method of controlling the heat treatment equipment of the present example configured as described above will be described. First, at the start of the heat treatment work of the electric resistance welded pipe 1, with respect to the side surface portion of the electric resistance welded pipe 1 transferred in the direction of the arrow G,
The mark C is marked by the marking means 4.

This mark C is detected by the upstream mark detector 5,
The twist value does not occur in the electric resistance welded pipe 1 and the seam welded portion A does not fluctuate, and the fluctuation value is detected by comparison with the reference value. Due to the fact that the amount of fluctuation of the seam welded portion A is proportional to the moving distance of the electric resistance welded pipe 1 in the transfer direction G, the above-mentioned fluctuation value detected by the detector 5 is substituted into a proportional expression for calculation. By processing information in this manner, the upstream mark detector 5
A fluctuation predicted position (shown by d in FIG. 1 on the downstream side of the cooling shower 8) of the seam welded portion A on the downstream side of the transfer direction G is calculated, and in this example, two predicted heating positions are used. As shown in FIG. 2, the upstream side inductors 7 and 7 are controlled to move to the proper corresponding positions directly above the seam welded portion A, whereby the seam welded portion A is appropriately heat-treated. Along with this, three sets of the downstream side inductor 9 and the downstream side mark detector 10 at the basic position, which are for integral tempering and the like, and the seam welded portion A corresponding to the respective installation positions are provided. Is controlled so as to move to the fluctuation predicted position (indicated by d in FIG. 1) and is made to stand by.

Next, the seam welded portion of the electric resistance welded pipe 1 passes through the cooling shower 8, and the seam welded portion A is rapidly cooled and transferred.
Due to the rapid cooling action at this time, a new secondary twist is generated in the electric resistance welded pipe 1, and the position of the seam welded portion A is displaced and re-changed, and detected by the upstream mark detector 5. It may deviate from the fluctuation predicted position d based on the value.
Along with this, the mark C also shifts from the position of C ₁ on the extension line of C on the downstream side of the quenching shower 8 to the position where the mark C re-displaces. In this case, in this example, since each downstream mark detector 10 is waiting on the predicted position C _{1 of the} mark corresponding to the predicted fluctuation position, the re-changing mark C may deviate from the detection range. However, this can be reliably detected. Then, when the mark C is detected by each downstream mark detector 10 in this way, the method of controlling the movement of each downstream inductor 9, 9, 9 is switched to that before that and each downstream mark detector 10 is switched. By controlling the movement of the downstream side mark detectors 10 just above the outer periphery of the actual position of the mark C that has newly changed during the rapid cooling detected by the above, the downstream side mark detectors 10 and The integrated downstream inductors 9 are respectively positioned directly above the actual seam welded portions A so that the subsequent heat treatment by induction heating is properly performed.

In this way, once the seam welded portion A is detected based on the mark detection results by the downstream side mark detectors 10, thereafter, the seam welded portion A is followed by the continuous marks C and is used for downstream such as tempering. Control the side inductor 9. When the heat treatment work of the seam welded portion is started as described above, the position control of the downstream inductor 9 is first performed based on the mark detection result of the upstream mark detector 5, and then the downstream mark detection is performed. The reason why switching is performed in two steps based on the mark detection result of the container 10 is as follows. That is, the position of the downstream side inductor 9 is directly determined based on the mark detection result by the downstream side mark detector 10 installed on the downstream side of the quenching shower 8 serving as a cooling unit, without performing the two-step position control as described above. If you try to control it, the distance from the welding point B is large at this position,
Moreover, since a secondary twist due to quenching is added, the amount of twist of the electric resistance welded pipe 1 is generally large, and the seam weld A
And the amount of change in the total position of the mark C is large. For this reason, in the position movement control of the downstream-side inductor 9, rapid follow-up movement of a large angle (for example, twice or more) is rapidly performed as compared with the above-described two-step position control, and a drive device therefor. 15 mag will be a big one. Further, since it is possible that the mark C deviates from the field of view of the downstream mark detector 10 and becomes undetectable, special measures such as making the field of view of the detector 10 particularly wide are necessary. However, in the above-described two-step position movement control of the present example, both the downstream inductor 9 and the downstream mark detector 10 are moved to the variation predicted position in advance based on the mark detection result by the upstream mark detector 5. Since it is waiting for the first waiting period, it is only necessary to move and control the downstream side inductor 9 for each tempering etc. at this waiting position to the actual position where secondary fluctuation due to rapid cooling is added. It is possible to shorten the movement time of the control operation in each of the movement to the position and the second movement to the actual position to shorten the operation time, and to make the drive operation mechanism and the like for the movement control into a compact and convenient structure. It will be possible. Further, the mark C does not deviate from the field of view of the downstream mark detector 10. Therefore, the start operation of the heat treatment work can be smoothly executed.

In particular, in the case of ERW pipe welding and heat treatment work using a finite length of pipe material, and ERW pipe welding and heat treatment work of large diameter pipes, continuous welding and heat treatment due to the short length of the pipe material. Working time is short. Then, each time welding of a new pipe material is started, the heat treatment work is frequently repeated. Therefore, it is very important to smoothly process the start of this frequent heat treatment work, and the above-mentioned effects are extremely remarkable.

In the above embodiment, the upstream mark detector 5
Is installed at a position between the heating inductor 7 and the cooling shower 8, and the movement of the heating inductor 7 is not controlled in accordance with the fluctuation of the seam welded portion A, or is controlled by other means. You may use the method. Further, the downstream side mark detector 10 as the downstream side variation detecting means is not mounted on all the downstream side inductors 9, but is mounted only on the first downstream side inductor downstream from the quenching section, or on the downstream side inductors. It is not installed on the downstream side, but is independently installed at a position between the quenching section and the downstream side inductor, and the position movement control of the downstream side inductor after the downstream side mark detector 10 detects the actual mark is performed. Fluctuation of the seam welded portion downstream from the quenching portion due to information processing in which the fluctuation amount detection result by the upstream side mark detector 5 and the fluctuation amount detection result by the downstream side mark detector 10 are compared and proportionally calculated. It is also possible to calculate the predicted position and control the position movement of each downstream inductor just above the outer circumference of the fluctuation predicted position. Further, it goes without saying that various means, such as optically detecting a mark of a bead cut on the seam welded portion A, which has been conventionally used, can be used as a means for detecting a change in the seam welded portion A.

H. Effects of the Invention As described in detail above, according to the position control method of the heat treatment equipment for ERW pipe seam welded portion of the present invention, the seam welded portion of the electric resistance welded pipe is rapidly cooled after heating and then reheated. In the case of starting the heat treatment work, the upstream side fluctuation detecting means detects the position fluctuation of the seam welded part due to the occurrence of twist of the electric resistance welded pipe during the transfer of the electric resistance welded pipe from the welding point to the cooling part, This fluctuation value is processed to calculate a fluctuation prediction position at least on the downstream side of the cooling unit, and corresponding to this fluctuation prediction position, downstream fluctuation detection means installed at least on the downstream side of the cooling unit, and a downstream The side inductor is controlled to move and wait at the position corresponding to the variation prediction. Therefore, next, by being rapidly cooled in the cooling unit,
The position of the seam welded portion is re-varied due to the secondary twist of the electric resistance welded pipe, which is added to the amount of fluctuation at the time of the initial transfer of the electric resistance welded pipe. As described above, when the movement prediction corresponding position reaches the basic position without waiting, the position of the downstream-side fluctuation detection means at the standby position is detected even if the amount of fluctuation deviates from the detection range. And the actual re-variation position of the seam welded portion is within the variation amount during the rapid cooling, the seam welded portion that has surely re-varied without deviating from the detection range by the downstream side variation detection means. There is an effect that it is easy to detect the variation value of.

Further, when controlling the movement of the downstream side inductor based on the detection result of the seam welded portion detected by the downstream side variation detecting means, the downstream side inductor already in the standby position is moved to the re-variation position of the seam welded portion. Since it only moves, the amount of movement is small, so that it can be quickly operated.
Further, as described above, in order to quickly move a large movement amount from the basic position to the re-change position without waiting for the movement to the fluctuation prediction corresponding position in advance, the drive mechanism is also enlarged, but As in the invention, the movement is made in two stages so that it moves forward from the basic position to the standby position, and then moves from the standby position to the re-variation position. The effect is that it can be simplified.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an example of the position control method of the heat treatment equipment for seam welds of electric resistance welded pipes of the present invention, and FIG.
-II line sectional view, FIG. 3 is a schematic side view showing an example of a conventional seam annealer, and FIG. 4 is a schematic side view showing an application example of the conventional technique. 1 ... ERW pipe, 4 ... Marking means, 5 ... Upstream mark detector, 7 ... Upstream inductor, 8 ... Cooling shower, 9 ... Downstream inductor, 10 ... Downstream mark Detector.

Claims (1)

[Claims] 1. When starting a heat treatment work in which a seam welded portion of a transferred electric resistance welded pipe is heated by an upstream side inductor, then rapidly cooled by a cooling part, and then reheated by a downstream side inductor, The position fluctuation of the seam welded portion which occurs during the transfer of the sewing pipe is detected by the upstream side fluctuation detecting means installed between the welding point and the cooling portion, and then the fluctuation amount is processed to be at least the cooling portion. Calculating the fluctuation predicted position of the seam welded portion on the more downstream side, and then installing the fluctuation predicted position at least between the downstream side inductor and the downstream side depending on the cooling part position at a position corresponding to the fluctuation predicted position. The downstream fluctuation detecting means of the seam welded portion is controlled to move, and then the actual position of the seam welded portion to which a new positional fluctuation is added in the cooling portion is detected by the downstream fluctuation detecting means. , Downstream guidance corresponding to this detection result Electric-resistance-welded pipe position control method of the heat treatment equipment seam weld characterized in that so as to move the control to the position opposed to the seam weld to.