JP2550246B2 - Non-consumable nozzle type two-electrode electroslag welding method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention electroslag-welds a groove formed by surrounding a side plate and a base material with two electrodes.
The present invention relates to a non-consumable nozzle type electroslag welding method.

[0002]

2. Description of the Related Art As a vertical automatic welding method, an electroslag welding method and an electrogas welding method are widely used. In particular, for welding the diaphragm blind portion of the steel box column used for buildings such as buildings, as a simple electroslag welding method, consumable nozzle type electroslag welding or, for example, as disclosed in Japanese Patent Publication No. 60-54146. Non-consumable nozzle electroslag welding is commonly used.

[0003]

On the other hand, with the recent increase in the height of buildings such as buildings, the thickness of the steel material of the box column used is extremely thick steel exceeding 60 mm. With the consumable nozzle type electroslag welding and the non-consumable nozzle type electroslag welding described above, welding with a plate thickness of at most about 60 mm is possible, and when the plate thickness becomes extremely thick steel, it melts at the edge of the groove. Defects occur.
For example, the skin plate 1 and the diaphragm 2 shown in FIG.
When a gap (groove) surrounded by the side plates 3 and 4 is welded by oscillating the nozzle 5 of one welding machine, the slag is solidified or semi-molten due to insufficient heat quantity, and proper electroslag welding is performed. It cannot be done, and defective penetration occurs at the edge of the open tip.

Therefore, in the case of extremely thick steel, the groove may be welded by two electroslag welders, but since the nozzles of different welding machines are inserted into the same groove, it takes time to prepare for welding. At the same time, the control at the time of welding may cause an erroneous operation because the two operation panels are operated individually. Further, the penetration of welding is large at both ends of the groove, and a penetration failure may occur at the center of the groove due to insufficient heat. Eg 2
When the individual nozzles 5 and 6 are inserted into the groove as shown in FIG. 5 (b) and they are welded at the same time without rocking, they are melted at the places shown in black in FIG. 5 (b). Defects may occur.

An object of the present invention is to obtain a good and uniform penetration without welding defects in electroslag welding of extremely thick steel.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a non-consumable nozzle type electroslag welding in which a groove formed by being surrounded by a side plate and a base material is simultaneously welded by two electrodes. The electrodes are oscillated in the same direction, and one of the electrodes is stopped at the open tip and the other is stopped near the center of the groove, and the welding current and welding voltage of each electrode are set to the same condition. The non-consumable nozzle type two-electrode electroslag welding method is characterized in that the power feeding nozzle is pulled up and driven so as to maintain the welding wire protrusion length as a value.

[0007]

The operation will be described below with reference to the drawings. FIG. 2 shows an overall outline of one electroslag welding machine used for carrying out the present invention, FIG. 3 shows a front view of a stand of the welding machine, and FIG. 4 shows a cross section taken along line 4a-4a of FIG. . First, the structure of the welding machine will be described with reference to these drawings. The clamp 7, which is placed on the upper end surface of the skin plate (FIG. 3) that is one of the base materials, has a U-shaped cross section, Like the simple vise, it has a U-shaped monopod with a screw 8 (Fig. 4) with a lever rod. The clamp 7 is placed on the upper end surface of the skin plate 1 in such a manner that the skin plate 1 is received between the legs, and is fixed to the skin plate 1 by tightening the screw 8. The clamp 7 has Tx1 in the X direction (horizontal direction orthogonal to the longitudinal direction Y of the skin plate 1).
The swinging mechanism 10 is mounted via the position adjusting mechanism 9 (FIG. 2).

The adjusting screw 11 (FIGS. 3 and 4) of the Tx1 position adjusting mechanism 9 extends in the Tx1 direction and is rotatably fixed to the clamp 7. Base 12 engaged with rail (not shown) on clamp 7 extending in the Tx1 direction
A nut (not shown) screwed to the adjustment screw 11 is fixed to the base, and when the adjustment screw 11 is turned clockwise, the base 12 moves to the right in FIG. 4, and when it is turned counterclockwise. The base 12 moves to the left. Base 1 of swing mechanism 10
2, two guide rails are fixed, and a carriage 13 is mounted on these rails. An electric motor 14 is connected to the carriage 13 via a rack and a pinion.
When the electric motor 14 rotates forward, the carriage 13 moves to the right in FIG. 3, and when the electric motor 14 rotates backward, the carriage 13 moves to the left. Knob 1 on the base 12
Screw rods 5 and 16 extending in the Y direction are rotatably mounted, and guide bars extend parallel to the screw rods and are fixed to the base 12. The threaded bar has a right-hand thread in the first half, a left-hand thread in the second half, and a support for the first magnet in the first half, and a second carrier in the second half. The support carriers of the magnet are screwed together, and these support carriers are supported by guide bars so as to be movable in the Y direction. The first magnet and the second magnet are provided for defining the left and right turning points of the swing of the carriage 13 in the Y direction. The upper end surface of the carriage 13 is provided with one magnetic sensor. When the magnetic sensor detects the magnetism of the first magnet, the electric motor 14 is de-energized and the electric motor 14 is biased in the forward direction. When the magnetic sensor detects the magnetism of the second magnet, the electric motor 14 is de-energized and the electric motor 14 is biased in the reverse direction. As a result, the carriage 13
Reciprocates (swings) in the Y direction. The swing width is expanded or narrowed by rotating the knobs 15 and 16 and widening or narrowing the gap between the first magnet and the second magnet. That is, by turning the screw rod, the swing width of the carriage 13 in the Y direction (this is the swing width of the power supply nozzles 5 and 6 in the Y direction) can be adjusted.

A stand trunk 17 is vertically (Z direction) erected on the carriage 13. The stand trunk 1
7 is inserted into the lower opening of the main trunk 18 of the stand. That is, the main stand 18 is set up vertically on the carriage 13 and can rotate around the Z axis. The rotation and the fixing are performed by adjusting the tightening of the lock lever 19. An arm 21 is supported by the main stand 18 via a vertical and horizontal slide mechanism 20. Z-axis slider 22
A Y-axis slider 23 is fixed to the arm 23, and the arm 21 penetrates the slider 23. The Y-axis slider 23 is also provided with a knob 25 for position adjustment in the Y direction similar to the knob 24 for position adjustment in the Z direction, a lock lever 27 similar to the lock lever 26, a rack, and a pinion.

By these, the T direction of the arm 21 in the Y direction is T2.
The position of (FIG. 2) can be adjusted. At the right end of the arm 21 (FIG. 3), a pulling up and spacing adjusting mechanism 28 is attached. First support plate 29 of pulling and spacing adjustment mechanism 28
Is rotatably connected to a pin 30 fixed to the right end of the arm 21 and extending in the X direction.
It can rotate in the x1 (Fig. 2) direction. A base of a ball joint 31 is fixedly attached to the first support plate 29, and a tip of an angle adjusting screw 32 is rotatably coupled to a connecting rod integrally continuous with the ball of the ball joint 31. The screw stem of the angle adjusting screw 32 is screwed into and penetrates the nut, and this nut is fixed to the right end of the arm 21. When the angle adjusting screw 32 is turned clockwise, the screw 32
Moves to the right in FIG. 3 and pushes the first support plate 29 to the right (FIG. 3) via the ball joint 31, so that the first
The support plate 29 rotates about the pin 30 in the counterclockwise direction in FIG.

When the adjusting screw 32 is turned counterclockwise, the screw 32 moves to the left in FIG. 3, which pulls the first support plate 29 to the left (FIG. 3) via the ball joint 31, The first support plate 29 rotates about the pin 30 in the clockwise direction in FIG. The angle adjusting screw 32 can adjust the angle (Rx1) of the first support plate 29 (the power supply nozzles 5 and 6 supported thereby) with respect to the vertical line. First support plate 2
Three guide rods 34 to 36 (FIGS. 3 and 4) penetrating the second support plate 33 are fixed to one end of the guide plate 9, and an opposite plate 37 (FIG. 3) is fixed to the other end thereof. ing. A space adjusting screw 38 is rotatably connected to the facing plate 37, but is integrally connected in the Y direction, and the adjusting screw is screwed to the second support plate 33. Since the second support plate 33 is guided by the guide rods 34 to 36 so as to be movable in the Y direction, when the space adjusting screw 38 is rotated clockwise, the second support plate 33 moves to the right in FIG. When it is turned counterclockwise, it moves to the left.

In this way, by the distance adjusting screw 38, the second supporting plate 33 relative to the first supporting plate 29 in the Y direction T3 (FIG. 2).
The position of can be adjusted. A speed reducer 39 is fixed to the first support plate 29, and an output shaft 40 thereof penetrates the first support plate 29 and the second support plate 33. The rotation shaft of the electric motor 41 is connected to the input shaft of the speed reducer 39. A first drive roller 42 is fixed to the output shaft 40. A key groove extending in the direction Y in which the output shaft 40 extends is engraved on the side circumferential surface of the output shaft 40, and the output shaft 40 penetrates the second drive roller 43 at the location where the key groove is present. Since the second drive roller 43 has a key protruding into the key groove,
It slides with respect to the output shaft 40 in the longitudinal direction Y but is mechanically connected in the rotational direction. As a result, when the electric motor 41 rotates forward, both the first and second drive rollers rotate forward. That is, this causes the power supply nozzles 5 and 6 to rise at the same speed.

In FIG. 4, a pin 44 is rotatably erected on the first support plate 29, and the pin 44 has the first pin 44.
The rotating arm 45 is fixed. First rotating arm 45
The first intermediate portion of the first drive roller 42 facing the first drive roller 42
A driven roller 46 is mounted. First rotating arm 4
A screw rod 47 extending in the X direction penetrates through the upper end of the No. 5.
One end of the screw rod 47 is rotatably connected to the first support plate 29 by a pin 44. At the other end of the screw rod 47, which penetrates the spring seat and the compression coil spring 49, an adjusting nut 50 is attached.
Are screwed together. When the adjusting nut 50 is tightened, the first rotating arm 45 is pressed to rotate counterclockwise via the compression coil spring 49 and the spring seat, and the first power supply nozzle 5 is pressed against the first drive roller 42. .
A pin 51 is rotatably erected on the first support plate,
An eccentric cam 53 having a lever 52 is fixed to the pin 51. When the lever 52 is rotated 90 degrees in the counterclockwise direction, the eccentric cam 53 rotates the first rotation arm 45 in the clockwise direction by 15 degrees against the repulsive force of the compression coil spring 49. Moves away from the first power supply nozzle 5. Two roller shafts are erected on the first support plate 29, and driven rollers 54 and 55 are rotatably mounted on these roller shafts.
4, 55 guide the first power supply nozzle 5 movably in the vertical direction Z. The gap between the driven rollers 54 and 55 can be adjusted with an adjusting screw 56.

A second power feeding nozzle lifting mechanism having the same structure as the first power feeding nozzle lifting mechanism which is a combination of the above-described first driving roller 42, first rotating arm 45, first driven roller 46, etc. The second support plate 33 (FIG. 3) is provided to support the second power supply nozzle 6, and the driven roller 57 and the adjusting screw 58, which are similar to the driven rollers 54 and 55 and the adjusting screw 56, are secondly supported. It is attached to the plate 33, and these guide the second power supply nozzle 6 movably in the vertical direction Z.

In the electroslag welding machine described above, the distance between the first power feeding nozzle 5 and the second power feeding nozzle 6 is adjusted by the distance adjusting screw 38 in a state of being mounted on the skin plate 1 as shown in FIG. T3 direction) With the angle adjusting screw 32, the power supply nozzles 5 and 6 are connected to the side plates 3,
4 can be adjusted in parallel (Rx1 direction). Further, the position adjustment knob 25 in the Y direction can adjust the Y direction positions of the power supply nozzles 5 and 6, and the Z direction position adjustment knob 24 can increase the height of the power supply nozzle pulling mechanism such as the first support plate 29. The height can be adjusted. Further, by loosening the lock lever 19 and rotating the stand main shaft 18 with respect to the carriage 13, the plane including both the power supply nozzles 5 and 6 can be adjusted parallel to the vertical plane of the skin plate 1, and the adjustment screw The position of the power supply nozzles 5 and 6 in the X direction can be adjusted with 11. In addition, the swing widths of the power supply nozzles 5 and 6 in the Y direction can be adjusted by turning the knobs 15 and 16. In FIG. 2, wire feeding devices 59 and 60 feed the welding wire wound around spools 61 and 62 to the power supply nozzles 5 and 6, and between the skin plate 1 and the power supply nozzles 5 and 6. , Welding power supply devices 63 and 64 supply welding current. Welding current, voltage value, power supply nozzles 5, 6
The rocking speed and pulling speed of are set on the operation panel 65.

[0016]

Example: Chemical composition shown in Table 1, plate thickness 70 mm, 80
2 mm and 100 mm SM490B steels were used to fabricate a test plate assuming the welding of the diaphragm blind portion of the box column as shown in FIG. The groove gaps were all 25 mm, and the length of the test plate was 750 mm.

[0017]

[Table 1]

Electroslag welding was performed with two electrodes under the welding conditions shown in Table 3 using commercially available wires having the chemical components shown in Table 2. The welding conditions were the same for both electrodes. Also, the slag bath depth during welding is 15 to 20 m.
At the start of welding, a medium manganese oxide-based flux was added so as to obtain m. The wire protrusion length L was set to L = 25 to 30 mm in both electrodes.

[0019]

[Table 2]

100 m from the start of welding after the end of welding
m, the central portion of the length of the test plate, and 100 mm from the weld crater portion, macro test pieces were sampled and examined for their welding defects. Also, from the welded part to JISZ
An impact test piece No. 4 of 3111 was sampled and tested.
The respective results are shown in Table 3.

[0021]

[Table 3]

As a result, the experimental NO. 1 to
In No. 5, the penetration was uniform, as shown in FIG. 5A, there were no welding defects, and the toughness of the weld metal was satisfactory. In the comparative example, the experiment NO. 6 has a plate thickness of 100 mm, the nozzle gap is 60 mm, and welding is performed without rocking, a penetration failure occurs due to insufficient heat in the groove portion.
It was like (b).

In the comparative example, the experimental NO. 7 is a plate thickness of 100 mm
Then, in the case of welding without rocking with the nozzle gap of 80 mm, the penetration at the open tip is good, but a penetration failure occurs at the center, and as shown in FIG. 5 (c). there were.

In the comparative example, the experimental NO. 8 is a plate thickness of 100 mm
When the first nozzle was set to 380A and the second nozzle was set to 350A, the left and right heat amounts were unbalanced and the left and right penetration directions in the rocking direction were uneven.

[0025]

As described above, according to the present invention, in electroslag welding of extremely thick steel, a simple and uniform penetration can be obtained, and a weld portion having no defect and excellent toughness can be obtained.
Therefore, the industrial utility value of the present invention is very high.

[Brief description of drawings]

FIG. 1A is an enlarged plan view of skin plate 1, diaphragm 2 and side plates 3 and 4 shown in FIG.
(B) is the 1b-1b sectional view taken on the line of (a).

FIG. 2 is a perspective view showing an outline of one electroslag welding machine for carrying out the present invention.

FIG. 3 is an enlarged front view of the electroslag welder shown in FIG. 2.

FIG. 4 is a sectional view taken along line 4a-4a of FIG.

FIG. 5 is a plan view showing a groove surrounded by a diaphragm, a skin plate and a side plate for performing electroslag welding.

[Explanation of symbols]

1: Skin plate 2: Diaphragm 3, 4: Side plate 5: First
Power supply nozzle 6: Second power supply nozzle 7: Clamp 8: Screw 9: Position adjustment mechanism 10: Swing mechanism 11, 56, 58: Adjustment screw 12: Base 13: Carriage 14: Electric motor 15, 16: Knob 17: Stand Root 18: Stand main body 19: Lock lever 20: Up / down, left / right slide mechanism 21: Arm 22: Z-axis slider 23: Y-axis slider 24, 25: Knob 26, 27: Lock lever 28: Pull-up and spacing adjustment mechanism 29: No. 1 support plate 30, 44, 48, 51: pin 31: ball joint 32: angle adjustment screw 33: second support plate 34, 35, 36: guide rod 37: opposing plate 38: interval adjustment screw 39, 73: reducer 40: shaft 41: electric motor 42: first
Driving roller 43: Second driving roller 45: First
Rotating arm 46: First driven roller 47: Screw rod 49: Compression coil spring 50: Adjustment nut 52: Lever 53: Eccentric cam 54, 55, 57: Driven roller 59, 60: Wire feeding device 61, 62: Spool 63, 64: Welding power supply device 65: Operation panel 66, 67: Welding wire 68: Slag 69: Molten metal 70: Welding metal 71, 72: Relay member t ₁ : Skin plate thickness t ₂ : Diaphragm thickness G: Open Tip gap L: Projection length of welding wire

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yuji Suzuki 20-1 Shintomi, Futtsu City Nippon Steel Co., Ltd. Technology Development Division (56) Reference JP-A-55-5118 (JP, A) Japanese Patent 52-10771 (JP, B2)

Claims (1)

(57) [Claims] 1. A non-consumable nozzle type electroslag welding method in which a groove formed by being surrounded by a side plate and a base material is welded at the same time with two electrodes. By moving one of the electrodes at the open tip and stopping the other near the center of the groove, the welding current and welding voltage of each electrode are set to the same condition, and the welding current projection at which the welding current reaches the target current value. A non-consumable nozzle type two-electrode electroslag welding method, which comprises pulling up and driving a power supply nozzle so as to maintain the length.