KR101572145B1 - Automatic Welding Robot for Submerged Arc welding and welding mathod of the same - Google Patents

Abstract

 The present invention relates to an automatic welding apparatus capable of welding a straight line on a X-axis and a Y-axis in a two-dimensional plane, and an automatic welding apparatus capable of automatically performing straight line welding and curved line welding in a two- The present invention relates to a welding apparatus and a welding method using the same, and more particularly, to a SAW automatic welding apparatus for a straight line welding line for performing a welding operation by moving along an X-axis rail and a Y-axis rail, The automatic welding apparatus includes a main controller provided on one of left and right sides of a frame, an upper rotor configured in an upper direction of the frame, A rotary body formed to protrude downward from a bottom surface of the upper rotating body; And a rotating device for rotating the upper rotating body, the rotating body, and the lower rotating body, a welder recognition device attached to the welded portion, and a rotating device for rotating the lower rotating body, And a welding method using the automatic welding apparatus.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic welding apparatus for submerged arc welding,

The present invention relates to an automatic welding apparatus for submerged arc welding, and more particularly, to an automatic welding apparatus capable of welding a straight line on an X-axis and a Y-axis in a two-dimensional plane, The present invention relates to an automatic welding apparatus for submerged arc welding capable of automatically performing straight line welding and curved line welding in a welding apparatus using the same.

Submerged arc welding (SAW) is an automatic welding method in which a solid wire is fed into a granular plex which is placed in front of it, and an arc is generated inside the plex, thereby being called an arc welding.

These SAWs have the advantages of deep penetration, low defect rate, high reliability of welding joints, low arc fusing and low welding fumes, which ensures a clean environment. , Storage tanks, etc., are used for the welding of plate materials which can be continuously welded.

However, the automatic welding system using the SAW technique can only weld the straight line on the X-axis and the Y-axis in the plane, and welding the curved line is not possible. This is because the automatic welding apparatus moves along the rails on the X-axis and the Y-axis.

When the SAW automatic welding apparatus is used in the ship drying process, the welding line generated in the ship drying process is formed into a two-dimensional straight line and a curved line, so that the welding of the straight line is performed by the SAW automatic welding apparatus, Is performed by manual operation of the welder.

The manual welding is not only very efficient in operation but also causes gouging and welding correction work using a quartz rod due to the occurrence of internal defects in the welds, which causes contamination of the workplace environment and is a typical avoidance work of welders It is true.

Figs. 8 and 9 are illustrations of a conventional SAW automatic welding apparatus. A conventional SAW automatic welding apparatus will be described with reference to the drawings.

As shown in the drawing, a conventional SAW automatic welding apparatus is provided with a welding material supplying unit 32 including a welding wire supplying device, a flux supplying and collecting device 32a, and the like as an upper plate of a frame 31, A torch vertical moving device 34, a torch horizontal moving device 35, a plexus spraying device 36, and a flex recovery device (not shown) 37, a welding wire feeder 38, and the like.

The X-axis frame 10, the X-axis rail 11, and the X-axis rail 10 are horizontally moved in the X-axis and Y-axis directions of the welded part 30 by known techniques such as a ball screw, a rack and pinion, A X-axis rail moving device 12 is provided, and a Y-axis rail 20 and a Y-axis rail moving device 21 are provided in a lower direction of the X-axis frame, and a main controller 40 are provided.

The conventional SAW automatic welding apparatus has an advantage that it can quickly and precisely realize optimal welding conditions that can realize high quality welding even by simple input using various welding conditions as a database in the main controller.

However, in the case of the curved line welding of the 1/4 circular, semicircular, and circular welding lines, since the welding is dependent on the manual welding of the welder, not only the function as the automatic welding device is insufficient, .

Korea Patent No. 10-0971329 Korea Patent No. 10-0609196 Korea public utility model 20-2014-0005828

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a submerged arc welding method capable of minimizing the improvement of the SAW automatic welding apparatus, And an object of the present invention is to provide an automatic welding apparatus for welding and a welding method using the same.

The problems to be solved by the present invention are not limited to the above-mentioned problems. It is to be understood by those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

The present invention relates to a SAW automatic welding apparatus for a straight line weld line moving along an X-axis rail and a Y-axis rail and performing a welding operation, the apparatus comprising: an X-axis rail and a Y-axis rail; And an automatic welding apparatus, wherein the automatic welding apparatus includes a main controller provided on one of left and right sides of a frame, an upper rotor configured in an upper direction of the frame, A lower rotating body coupled to a bottom surface of the rotating body; a welding portion provided on a bottom surface of the lower rotating body; and a welding portion attached to the welding portion An automatic welder for submerged arc welding comprising a welder recognition device for rotating the lower rotating body, a rotating body for rotating the upper rotating body, a rotating body, and a lower rotating body, Characterized by a soft welding method.

The present invention can automatically perform welding of a curved welding line by constituting an upper rotating body, a rotating body, a lower rotating body, and a rotating device in a SAW automatic welding apparatus which can move linearly in a conventional plane. Accordingly, it is possible to prevent welding defects caused by manual welding of the conventional curved welding line, to reduce the time required for manual welding, to eliminate inconvenience caused by the receiving welding operation, to improve the welding quality by uniform welding, There is an effect of speeding up.

In addition, the present invention has the effect of preventing occurrence of an arc interruption by automatically welding straight and curved welding lines, eliminating the need for a gouging operation for correcting welding defects, and preventing work avoidance of welding workers.

1 is a perspective view illustrating the entire configuration of the present invention.
2 is a perspective view showing an automatic welding apparatus of the present invention.
3 is a front view showing an automatic welding apparatus according to the present invention.
4 is a partially enlarged cross-sectional view showing the rotating device of the present invention.
5A and 5B are perspective views showing the rotational action of the present invention.
6 is an exemplary view showing an embodiment of a weld line for explaining a welding method according to the present invention.
7 is a block diagram showing a welding method according to the present invention.
8 is a frontal view showing a conventional SAW automatic welding apparatus.
9 is a side view illustrating a conventional SAW automatic welding apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The known configurations and their associated operations are omitted or briefly described, and the size of each element or a specific portion constituting the element in the drawings may be exaggerated, omitted, or schematically shown for convenience and clarity of description .

1 is a perspective view illustrating the entire configuration of the present invention. The overall structure of the present invention will be described with reference to the drawings.

As shown in the figure, the present invention provides an SAW automatic welding apparatus for a straight weld line, comprising an X-axis rail 100 and a Y-axis rail 200, an X-axis rail moving device 110 and a Y- And an automatic welding apparatus 300, The X-axis rail moving device moves the automatic welding device along the X-axis rail in the X-axis direction and the Y-axis rail moving device moves the automatic welding device along the Y-axis rail in the Y-axis direction. Perform the operation.

The X-axis rail moving device 110 and the Y-axis rail moving device 210 are known technologies for moving along the rails. The SAW operation of the automatic welding device is also a well-known technique, and thus a detailed description thereof will be omitted.

2 is a perspective view showing an automatic welding apparatus of the present invention. The automatic welding apparatus will be described with reference to the drawings.

Referring to the drawings, the automatic welding apparatus 300 includes a main controller 314 provided at one of left and right sides of a frame 310, an upper rotating body 320 configured in an upper direction of the frame, A rotary body 330 protruding downward from a bottom surface of the upper rotating body 320 and a lower body 330 coupled to a lower surface of the rotating body 330. [ A rotating body 330 and a lower rotating body 340. The upper rotating body 320 and the rotating body 330 are rotatably supported by a lower portion of the lower rotating body 340, And a rotating device 360 for rotating the rotating member 360.

The automatic welding apparatus 300 moves linearly along the X-axis and Y-axis rails under the control of the main controller and performs straight line welding, and by the operation of the rotating device, the upper rotor, the rotating body, Is rotated up to 360 degrees and curved line welding is performed. The welding portion is configured to be spaced apart from the center of the lower rotating body, and the spacing distance is also adjustable. Accordingly, when the upper rotating body, the rotating body, and the lower rotating body are rotated with respect to the center of the rotating body, the welded portion can perform curved line welding such as a ¼ circular, semicircular, or circular line with respect to the center point of the rotating body.

2 is a perspective view showing an automatic welding apparatus according to the present invention, and FIG. 3 is a front view showing an automatic welding apparatus according to the present invention. The automatic welding apparatus will be described in detail with reference to the drawings.

As shown in FIG. 2, the frame 310 is formed of a top frame 311 and a guard frame 313, to which a plurality of polygonal pipes are coupled. The upper frame 311 is formed at the upper end of the frame 310 and has a rotation space 312 formed at an inner center thereof. The guard frame 313 extends in the downward direction from both left and right ends of the upper frame 311 Respectively. The X-axis rail moving device 110 is coupled to the rear of the guard frames 313, and the X-axis rail moving device is connected to the X-axis rail, so that the frame is not rotatable. A main controller 314 is fixed to one side of both guard frames 313.

The upper frame 311 and the guard frame 313 constitute the skeleton of the automatic welding apparatus 300. The upper frame 311 includes an upper rotor 320, a rotating body 330, a lower rotor 340 And the guard frame 313 protects the welded portion 350 on the bottom surface of the lower rotating body from external impact.

Referring to FIG. 2, the upper rotating body 320 is formed in a circular or polygonal shape in the upward direction of the frame 310 as a plate. An upper through hole 321 is formed at the center of the upper rotating body 320. The upper surface of the upper rotating body is provided with a welding material supplying unit 322 including a welding wire supplying device, a flux supplying and collecting device 355 and the like necessary for welding. In each apparatus of the welding material supply unit 322, a welding material supply line 323 extends downward through the upper through-hole 321.

As shown in FIG. 3, the rotating body 330 has a cylindrical shape with a flange 331 formed at the lower end thereof. The rotating body 330 is engaged with and fixed to the bottom surface of the upper rotating body 320. The joint fixation is a mechanical joint such as welding or fastening of a bolt and a nut. A central through hole 332 is formed in the rotating body 330, and the central through hole is formed to pass from the upper end to the lower end of the rotating body. A welding material supply line 323, which is lowered through the upper through-hole 321, extends downward in the central through hole 332.

Referring to FIG. 3, the lower rotating body 340 is formed in a circular, oval or polygonal shape. The lower rotating body 340 is engaged with and fixed to the bottom surface of the flange 331 of the rotating body 330. The engagement fixation is also a mechanical engagement such as welding or fastening of bolts and nuts. A lower through hole 341 is formed at the center of the lower rotating body. The lower through-hole 341 extends downward through the upper through-hole 321 and the through-hole 332 through the welding material supply line 323.

As shown in Fig. 3, the welded portion 350 is formed on the bottom surface of the lower rotating body 340. As shown in Fig. The welding portion 350 is configured to protrude downward from one side of the left or right side of the lower rotating body 340. The welding portion 350 includes a welding torch 351, a welding wire feeder, a torch vertical movement device 352, a torch horizontal movement device 353, a plex spray device 354, a flex recovery device 355, 356) and the like. The welding material supply line 323 is finally connected to the welded portion 350 through the upper through hole 321, the central through hole 332 and the lower through hole 341. Since the welding portion 350 is a well-known structure of the SAW automatic welding device, detailed description of the construction and operation will be omitted.

3, the weld seam recognition device 356 comprises a first sensor 356a at the bottom center of the lower rotator 340 and a second sensor 356b provided between the two welding torches 351 . The weld seam recognition device 356 is preferably a laser sensor as a device for recognizing a weld line, but may be a mechanical sensing means such as a metal piece or the like. The position of the first sensor is the same as the center of rotation of the upper rotating body, the rotating body, and the lower rotating body as the bottom center of the lower rotating body. The position of the second sensor 356b is between two welding torches, and the position of the sensor is changed according to the position of the welding torch.

4 is a partially enlarged cross-sectional view showing the rotating device of the present invention. The rotating device will be described with reference to the drawings.

Referring to the drawings, the rotating device 360 is provided on the lower outer periphery of the rotating body 330 and the upper plate of the lower rotating body. The rotary device 360 includes a bearing inner race 361, a guide ring 362, a bearing outer race 363, a rotary driven gear 364, a rotary motor 366, and a rotary drive gear 365 .

The bearing inner race 361 is fastened to the upper surface of the flange 331 of the rotating body 330. The fastening means such as a bolt used in the above-described fastening fixes the bearing inner race 361, the rotating body 330, and the lower rotating body 340 together. The bearing inner race is part of a bearing assembly for rotating the upper rotor, the rotating body, and the lower rotor.

The guide ring 362 is fastened to the bottom surface of the frame 310 and the bearing outer race 363 is provided on the bottom surface of the guide ring 362. The fastening means used in the above-described fastening fixes the frame, the guide ring, and the bearing outer race together. The guide ring 362 is connected to a guide provided on the upper surface of the lower rotating body to guide stable rotation of the upper rotating body, the rotating body, and the lower rotating body.

The bearing outer race 363 is in contact with the outer periphery of the bearing inner race 361 and a plurality of bearing balls are provided between the bearing outer race and the bearing inner race so that the bearing inner race, do. Accordingly, the rotating body 330 having the bearing inner race fastened thereto is rotatable within the frame, and the upper rotating body 320 coupled and fixed to the rotating body 330 and the lower rotating body are also rotatable.

A rotation driven gear 364 is formed around the outer periphery of the bearing outer race 363 and the rotation driven gear 364 is engaged with the rotation drive gear 365 of the rotation motor 366. The rotary motor 366 is fixed on the upper surface of the lower rotating body 340 in a state where a part of the rotary motor is buried.

5A and 5B are perspective views showing the rotational action of the present invention. The rotation operation of the present invention will be described with reference to the drawings.

When the rotary drive gear is rotated by the operation of the rotary motor, the rotary driven gear which is in contact with the rotary drive gear rotates. The rotation driving gear is coupled and fixed to the bottom surface of the non-rotatable frame 310. The rotation motor and the rotary drive gear are engaged with and fixed to the rotatable lower rotator 340, As shown in Fig.

Since the lower rotating body 340 is fixedly coupled to the rotating body 330 and the upper rotating body 320 by mechanical coupling, the set rotates at the same time. The welding material supply line extending from the welding material supply portion 322 formed at the uppermost stage in the above-described rotation operation extends to the weld portion 350 through the upper through hole, the central through hole, and the lower through hole. Each of the through holes is formed in the center of rotation of the upper rotating body, the rotating body, and the lower rotating body, and the welding material supplying line extends downward through the center of rotation. Therefore, twisting of the welding material supply line due to rotation is prevented, and smooth rotation action becomes possible.

The positional shift of the welding torch according to the radius change of the curved welding line is performed according to the operation of the torch horizontal moving device 353. By the operation of the torch horizontal moving device, the welding torch 351 is spaced from the center of the lower rotating body 340, and the spacing is adjusted to be equal to the radius of the curved welding line.

6 shows an embodiment of a welding line for explaining a welding method. An embodiment of the welding line will be described with reference to the drawings. In the description with reference to FIG. 6, the horizontal direction of the drawing is defined as the X-axis, and the vertical direction of the drawing is defined as the Y-axis.

The center point X shown in the figure indicates the center of the lower rotating body and is the sensing position of the first sensor. The welding point O shown in the figure indicates the center of the two welding torches, Sensing position.

The welding line is a two-curved welding line (A) formed of three straight-line welding lines and a 1/4 circular shape, and is generally shaped like '⊃'. The first welding line H1 is located at the top of the drawing in the two lateral welding lines and the second welding line H2 is located at the bottom of the drawing in the two lateral welding lines. The Y-axis welding line (V) means a longitudinal direction welding line. The plate piece P formed on one side of the first welding line H1 is a starting point of welding and is provided on one side of the second welding line H2 The formed plate P is the welding end point.

7 is a block diagram showing a welding method according to the present invention. A curved welding method according to the present invention will be described in detail with reference to the drawings. In the following description, the first welding line, the second welding line, the Y-axis welding line and the center point, the welding point, and the flat plate are as defined in Fig.

(S100) for preparing a submerged arc welding operation: the fact that the X-axis first welding line, the second welding line and the Y-axis welding line are present is input to the main controller, and based on the radius Adjust the welding point according to the radius of the curved welding line by adjusting the distance between the center point of the lower rotating body and the welding point.

Second step of recognizing the first welding line (S200): The automatic welding device moves in the Y-axis lower direction and the welding spot recognizes the first welding line.

(S300): The automatic welding apparatus moves in the leftward direction of the X axis so that the welding point recognizes the plate piece formed on one side of the first welding line, that is, the welding starting point, but the center point is one side of the first welding line That is, recognizes the deviation from the welding starting point, and recognizes the point where welding is started.

Fourth step of recognizing the Y-axis welding line (S400): After the welding point of the upper rotating body, the rotating body, the lower rotating body and the welding portion of the automatic welding apparatus is rotated 90 degrees clockwise with respect to the center point, Moves in the lower direction of the Y axis, and moves in the right direction of the X axis, and the welding spot recognizes the Y axis welding line.

The fifth step of recognizing the second welding line (S500): After the welding point of the upper rotating body, the rotating body, the lower rotating body, and the welding portion of the automatic welding machine is rotated clockwise 90 degrees with respect to the center point, Moves in the leftward direction of the X axis, and moves in the downward direction of the Y axis so that the welding spot recognizes the second welding line.

(S600): The automatic welding apparatus moves in the leftward direction of the X axis so that the welding point recognizes the plate piece formed on one side of the second welding line, i.e., the welding end point, but the center point is one side of the second welding line That is, the welding end point, and recognizes the point where the welding is finished.

(S700): the welding point of the upper rotating body, the rotating body, the lower rotating body, and the welding portion of the automatic welding apparatus is rotated 180 degrees in the clockwise direction, and then the entire automatic welding apparatus is moved to the Y axis Moves upward and moves the welding spot to the welding start point.

Eighth step (S800) in which the submerged arc welding operation proceeds; the automatic welding apparatus welds the straight welding line and the curved welding line along the recognized welding line.

The present invention prevents the occurrence of arc breaks by automatically welding straight and curved weld lines continuously without interrupting the welding operation, and also prevents the work of correcting weld defects and improves the welding quality by uniform welding.

In the present invention, the Y-axis welding line and the two 1/4 circular welding line are provided between the first welding line and the second welding line. However, In the embodiment in which the circular weld line is formed, step 4 is excluded.

It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention as set forth in the following claims. Should belong to the scope of claims of the attached patent registration.

X-axis rail: 100 Y-axis rail: 200
X-axis rail movement device: 110 Y-axis rail movement device: 210
Automatic welding equipment: 300 frames: 310
Top frame: 311 Rotating space: 312
Guard Frame: 313 Main Controller: 314
Upper rotating body: 320 Upper through hole: 321
Welding material supply part: 322 Welding material supply line: 323
Rotating body: 330 Flange: 331
Center through hole: 332 Lower rotation: 340
Lower through hole: 341 Welding area: 350
Welding torch: 351 Torch Vertical movement: 352
Torch horizontal movement device: 353 Flexspot device: 354
Flex picking device: 355 Welding line recognizing device: 356
First sensor: 356a Second sensor: 356b
Rotating device: 360 bearing inner race: 361
Guide Ring: 362 Bearing Outer Lace: 363
Rotating Driven Gear: 364 Rotary Drive Gear: 365
Rotary Motor: 366

Claims (5)

1. A SAW automatic welding apparatus for a linear weld line for performing a welding operation along an X-axis rail and a Y-axis rail,
An X-axis rail moving device 110 and a Y-axis rail moving device 210, and an automatic welding device 300, the X-axis rail 100 and the Y-axis rail 200,
The automatic welding apparatus 300 includes a main controller 314 provided on one of left and right sides of the frame 310,
An upper rotating body 320 configured in an upper direction of the frame,
A welding material supply unit 322 provided on the upper surface of the upper rotating body,
A rotating body 330 protruding downward from a bottom surface of the upper rotating body 320, a lower rotating body 340 coupled to a bottom surface of the rotating body 330,
A weld portion 350 provided on the bottom surface of the lower rotating body, a weld line recognition device 356 attached to the weld portion,
And a rotating device (360) for rotating the upper rotating body (320), the rotating body (330), and the lower rotating body (340).
The method according to claim 1,
The frame 310 is formed by a top frame 311 and a guard frame 313 to which a plurality of polygonal pipes are coupled. The top frame 311 is formed at the upper end of the frame 310, The guard frame 313 extends downward from both left and right ends of the upper frame 311 and extends rearward of the guard frames 313 by an X-axis rail moving device 110 And the X-axis rail moving device 110 is connected to the X-axis rail 100 so that the frame 310 is configured to be non-rotatable,
The upper rotating body 320 is formed in a circular shape or a polygonal shape in the upper direction of the frame 310 as a plate shape. An upper through hole 321 is formed at the center of the upper rotating body 320, A welding material supply unit 322 including a welding wire supply unit for welding, a flex supply and recovery unit 355 and the like is provided on the upper surface of the welding material supply unit 322. In each of the welding material supply unit 322, Is extended downward through the upper through hole 321,
The rotating body 330 has a cylindrical shape with a flange 331 formed at the lower end thereof and is fixedly coupled to a bottom surface of the upper rotating body 320. Inside the rotating body 330, A hole 332 is formed in the central through hole 332 and a welding material supply line 323 extending through the upper through hole 321 extends downward,
The lower rotating body 340 is fixedly coupled with the bottom surface of the flange 331 of the rotating body 330 as a plate shape and a lower through hole 341 is formed at the center of the lower rotating body, The welding material supply line 323, which is lowered through the upper through hole 321 and the central through hole 332, extends downward,
The lower portion of the lower rotating body 340 is provided with a welding portion 350 protruding downward from one side of the left or right side of the lower rotating body 340. The welding portion 350 includes a welding torch 351, A torch vertical movement device 352, a torch horizontal movement device 353, a plex spray device 354, a flex recovery device 355, a weld line recognition device 356,
Wherein the welding material supply line is coupled to the weld 350. The automatic welding device of claim 1,
The method according to claim 1,
The rotating device 360 is provided on the lower outer circumference of the rotating body 330 and on the upper plate of the lower rotating body and includes a bearing inner race 361, a guide ring 362, a bearing outer race 363, A gear 364, a rotary motor 366, and a rotary drive gear 365,
The bearing inner race 361 is fastened to the upper surface of the flange 331 of the rotating body 330. The bearing inner race 361, the rotating body 330 and the lower rotating body 340 are fixedly engaged,
The guide ring 362 is fastened to the bottom surface of the frame 310 and a bearing outer race 363 is provided on the bottom surface of the guide ring 362. The frame 310, the guide ring 362, the bearing outer race 363 are coupled and fixed, and the guide ring 362 is connected to a guide provided on the upper surface of the lower rotating body to guide stable rotation of the upper rotating body, the rotating body, and the lower rotating body,
The bearing outer race 363 is in contact with the outer periphery of the bearing inner race 361. A plurality of bearing balls are provided between the bearing outer race and the bearing inner race to constitute a bearing assembly,
The rotation driven gear 364 is engaged with the rotation drive gear 365 of the rotation motor 366 and rotatably supported by the rotation motor 366, Wherein a portion of the rotating motor is fixed in a state of being buried in the upper surface of the lower rotating body (340).
The method of claim 2,
The weld seam recognition device 356 comprises a first sensor 356a at the bottom center of the lower rotator 340 and a second sensor 356b provided between the two welding torches 351,
The position of the first sensor is the same as the center of rotation of the upper rotating body, the rotating body, and the lower rotating body, and the position of the second sensor 356b is the position between the two welding torches Characterized in that the position of the sensor is changed according to the position of the torch.
The horizontal direction of the drawing is defined as an X-axis, and the vertical direction of the drawing is defined as a Y-axis. The center point X means the center of the lower rotating body and is the sensing position of the first sensor. Refers to the center of the two welding torches and is the sensing position of the second sensor. The welding line is a two curved welding line (A) formed of three linear welding lines and a quarter circular, The first welding line H1 is located at the top of the figure among the two lateral welding lines and the second welding line H2 is located at the bottom of the figure among the two lateral welding lines, The plate piece P formed on one side of the first welding line H1 is welded to the welding start point H, , And the plate piece P formed on one side of the second welding line H2 A welding method using an automatic welding apparatus for submerged arc welding for welding a welding line formed by a welding end point,
Preparing a submerged arc welding operation;
Recognizing the first welding line;
Recognizing the welding start point;
Recognizing the Y-axis weld line;
Recognizing the second weld line;
Recognizing the welding end point;
Moving the welding point toward a welding start point;
And a submerged arc welding operation is performed on the submerged arc welding operation.

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