JPS6054146B2 - Electroslag welding method and its equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a welding method and apparatus for electroslag welding a groove formed by surrounding a filler metal and a base metal.

Electroslag welding has been widely used as a vertical automatic welding method.

This welding method uses a water-cooled copper dowel that slides up as welding progresses to prevent molten metal from dripping. J The welding equipment that implements this method requires an automatic lifting device and a swinging device for the power supply nozzle, and a sliding pressing device for the water-cooled copper dowel, which has the disadvantage that the entire device becomes complicated and large. Another disadvantage is that it is not possible to weld within a groove surrounded by base metal abutment steel plates on four sides, such as in the diaphragm blank part of a steel box column. On the other hand, a consumable nozzle type electroslag welding method is currently widely used as a simple electroslag welding method.

In this welding method, the copper dowel is tightly fixed to the base metal from the beginning, and welding is performed by consuming a power supply nozzle made of steel pipe or coated steel pipe.Compared to the electroslag welding method described above, the welding equipment is It has the advantages of being simple and easy to move, making it easy to prepare for welding, and being able to weld the blind part of the diaphragm of a steel box column. However, because the dry extension of the wire is small, the melting speed of the wire is slow and efficiency is high. There are bad drawbacks. In other words, when the current is constant, the longer the dry extension of the wire, that is, the protruding part of the wire, the greater the resistance heat generation of the wire and the faster the melting speed, and the shorter the wire resistance heat generation becomes. It gets smaller and slower.

In the case of the electroslag welding method described above, the wire has a long dry extension of 30 to 707 m, so the melting rate of the wire is fast, but in the case of the consumable nozzle type electroslag welding method, the melting speed of the wire is 0 to 577!77 m. Since the wire is very short, the wire melting speed is slow, resulting in a decrease in efficiency.

In addition, since steel pipes are used for power supply, the current conductivity is inferior to non-consumable copper power supply nozzles, the same number of consumable nozzles as the number of welded joints is required, and when flux-coated steel pipes are used for consumable nozzles, fluorine. There are disadvantages such as the fact that the wax easily absorbs moisture and there is a risk of creating defects in the welded area due to moisture.

The present invention provides a welding method and welding device that solve the above problems. That is, the present invention provides a power supply nozzle inserted into the groove in the vertical advancement electroslag welding method for welding a groove formed by surrounding the welding metal and the base metal. The welding wire is clamped by the nozzle clamping rollers and fed through the power supply nozzle to start welding, and the clamping rollers are rotated as welding progresses while maintaining the dry ex-1 tension of the welding wire at a constant length. , an electroslag welding method characterized by welding by pulling up a power supply nozzle, and an apparatus for implementing this method. In order to easily understand the present invention, the welding method of the present invention will be explained based on FIGS. 1 to 4.

FIG. 1 is an explanatory diagram showing one embodiment of the method of the present invention, in which 1 is a base material, 2 is a power supply nozzle, 3 is a driving clamping roller, 4 is a pressure clamping roller, 5 is a guide clamping roller, Together with the motor 6, it constitutes a power supply nozzle elevating mechanism.

The power supply nozzle 2 is a non-consumable nozzle whose power supply part is made of a material with good current conductivity, such as copper or copper alloy, and is surrounded by a base material 1, a fixed copper water cooling plate 9, and a backing steel plate 10. The welding wire is inserted into the groove, and at the same time as electricity is applied, an arc is generated between the tip of the welding wire and the base metal 1, flux is introduced, a molten slag pool 11 is created, and slag welding is started.

When welding starts and progresses, the welding current is detected so as to keep the dry extension 8 of the welding wire 7 at a set value, usually 30 to 50 wgn, and the clamping roller 3 is driven as the molten metal 12 rises. The power feeding nozzle 2 is pulled up and upward welding is performed. Next, FIGS. 2 and 3 show side views of embodiments of the apparatus used in the present invention, and FIG. Front view of main parts, No. 5
The figure is a sectional view taken along the line AA in FIG. 3.

In the figure, the non-consumable power supply nozzle 2 is held between a roller 3 driven by a motor 6 for raising and lowering the nozzle and a roller 4 which is pressurized by a pressure screw 21, and the other part is held by a roller 5. It is clamped and held within the bevel and its extension.

Furthermore, these members are held by a plate 14.
In the embodiment of the device shown in FIG. 2, the plate 14 is connected to a clamp part 16 via a support part 15. 17 is a clamp screw for fixing the device to the base material 1.

The example device shown in FIGS. 3 and 5 has a swinging and swinging stop mechanism, and the plate 14 is connected to the sliding shaft 1.
It is connected to a slider 23 that is slidably provided at 9.

The slider 23 has a rack 27 that converts the rotational motion of the motor 20 transmitted from a pinion 28 attached to the motor 20 into linear motion, and a stop time attached to both ends of the feed screw 26. Limit switch 25 connected to a timer circuit (not shown)
, rotate the motor 20 in the reverse direction, and press the slider 23.
A protrusion 24 is provided for moving the motor in the direction of an arrow 22. This swing width is determined by adjusting the adjustment knob 18 at the end of the feed screw 26.
It can be set depending on the degree of rotation. These members are connected to a clamp section 16 via a support section 15. As explained above, according to the present invention, the device can be made smaller and lighter, so when the welding device is set up prior to the start of welding, it can be easily set on the base material using a clamp screw.

In addition, to prevent molten metal from dripping, not only can a simple fixed copper plate be used, but also four-sided base metals that do not use fixed copper plates, bevels in steel frame box columns diaphragm blind parts surrounded by steel plates, etc. Welding is possible because the power supply nozzle can be inserted from the top of the groove.

Since the power supply nozzle is held and raised by the two pairs of holding rollers, stable welding is performed without any fluctuation in the nozzle tips of the pair. Although three or more pairs of clamping rollers may be used, a sufficient effect can be obtained with two pairs. In addition, the applicable welding length can be extended simply by increasing the length of the power supply nozzle. If you use a device with a swing and swing stop mechanism, the power supply nozzle will swing in the direction of the plate thickness, making it possible to weld extremely thick plates, and by using the swing stop, it will be possible to weld the front and back sides of the groove. A welded part without defects such as defects can be obtained.

The effects of the present invention will be specifically illustrated by examples.

Example 1 Power supply nozzle has an inner diameter of 2.27Tt! n1 outer diameter 10
A Tfrm copper tube was used, and the outside was coated with an insulating heat-resistant material having a thickness of about 1 Tf$L.

A 50 kg class high tensile strength steel with a plate thickness of 20 mInl and a groove gap of 18 mm and an I-type groove shape was used as the test material. The welding was carried out using the following equipment.

Solid wire current of welding wire outer diameter 16: 40
0A Voltage: 40V Dry extension setting value: 407T! As a result of welding under conditions of In or higher, welds with no defects and a good bead appearance were obtained, and the welding speed was 5.6C77! / minute.

On the other hand, when the same groove was welded using the consumable nozzle type electroslag welding method, defects due to poor fusion occurred at the starting part.

Further, the welding speed was slow at 3.2 cm/min. Example 2
The same nozzle as in Example 1 was used, and the plate thickness was 38 mm as the test material.
? Using 50 kg class high tensile strength steel with a groove gap of 20 W$t and an I-shaped groove, the front and back sides of the groove were surrounded by copper plate pads and welded using the apparatus shown in FIG. 3.

Flux-cored rewiring of welding wire with outer diameter of 1.6
Current: 440A Voltage: 44V Dry extension setting value: 4h Number of oscillations: 2 (2)/min Oscillation width: 207m Oscillation pause time: 0. 2/1 oscillation cycle
As a result of welding under the above conditions, a welded part with good bead appearance without insufficient penetration was obtained, and the welding speed was 3.5 cm/min.

On the other hand, when the same groove was welded using the consumable nozzle type electroslag welding method, insufficient penetration occurred in a part of the groove.

Also, the welding speed is 2.1C7! / minute. As described above, according to the welding method and apparatus of the present invention, highly efficient electroslag welding can be performed with a simple work procedure, and is of great industrial value.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the method of the present invention, FIGS. 2 and 3 are side views of an apparatus according to an embodiment of the present invention, and FIG.
The figure is a front view of a main part of the apparatus according to the embodiment shown in FIGS. 2 and 3, and FIG. 5 is a sectional view taken along the line AA in FIG. 3. 1...Base material, 2...Power nozzle, 3.
...Drive port-ra, 4...Pressure roller, 5
....Guide roller, 6.. Lifting motor, 7..Welding wire, 8.Dry extension, 9..Filling copper plate, 10...
... Steel plate, 11 ... Molten slag pool, 1
2... Molten metal, 13... Welded metal, 1
4... Plate, 15... Support part,
16... Clamp part, 17... Clamp screw, 18... Adjustment knob, 19...
・Sliding axis, 20... Motor, 21... Pressure screw, 22... Rocking direction, 23...
Slider, 24...Protrusion, 25...Limit switch, 26...Feed screw, 27...
Rack, 28...pinion.

Claims (1)

[Claims] 1. A power supply nozzle inserted into the groove and provided on an extension of the welding line in the vertical advancement electroslag welding method for welding a groove surrounded by a metal and a base metal. The welding wire is clamped by clamping rollers and fed through the power supply nozzle to start welding, and while the dry extension of the welding wire is maintained at a constant length, the clamping rollers are rotated as welding progresses, and power is supplied. Electroslag welding method is characterized by welding by pulling up the nozzle. 2. In a vertical advancement electroslag welding device for welding a groove formed by surrounding metal and base metal, a power supply nozzle having a pipe shape that can be inserted from the upper end of the groove is provided in the groove, and the welding two pairs of clamping rollers are provided for enabling wire to be fed through the feed nozzle and for retaining the feed nozzle within and on an extension thereof, at least one of the rollers being coupled to a motor; An electroslag welding device characterized in that the power feeding nozzle is a driving roller that moves up and down. 3. In a vertically advancing electroslag welding device for welding a groove formed by surrounding metal and base metal, a power supply nozzle having a tube shape that can be inserted from the upper end of the groove is provided in the groove, and the welding two pairs of clamping rollers are provided for enabling wire to be fed through the feed nozzle and for retaining the feed nozzle within the bevel and on its extension, at least one of the rollers being coupled to a motor; a driving roller for raising and lowering the power supply nozzle, a swinging mechanism for swinging a plate provided with the clamping roller, and a stop mechanism for temporarily stopping the swinging of the plate at one end or both ends of the swinging width. An electroslag welding device comprising: