CN110977101B - Method for automatically pulse MIG surfacing welding of aluminum bronze on upstream and downstream flanges - Google Patents

Abstract

The invention discloses an automatic pulse MIG (metal-inert gas) surfacing method for upstream and downstream flanges, which is realized by carrying out automatic pulse MIG (metal-inert gas) surfacing on the inner surfaces of fixed upstream and downstream flanges through a movable welding robot.

Description

Method for automatically pulse MIG surfacing welding of aluminum bronze on upstream and downstream flanges

The technical field is as follows:

the invention relates to the field of pumped storage, in particular to an automatic pulse MIG (metal-inert gas) surfacing method for upstream and downstream flanges.

Background art:

the aluminum bronze is bead-welded on the side wall of the upstream flange and the downstream flange of the pumped storage ball valve, so that the abrasion resistance of the surface can be improved, the diameter of the upstream flange and the downstream flange is 2000 mm-4000 mm, and the bead-welding height of the aluminum bronze is 40 mm-150 mm. The traditional manufacturing process adopts manual surfacing welding or adopts a welding trolley matched with a positioner to perform surfacing welding on a flange surface, and has the following problems:

1) the physical properties of the aluminum bronze, such as thermal expansion coefficient and the like, of the dissimilar material base metal are greatly different, the weldability is poor, the welding repair rate is high, the manual surfacing welding quality is unstable, and a welding process with stable quality is required;

2) the inner wall surfacing of the large flange part needs to be matched with a large positioner, so that the manufacturing cost is increased, and the workpiece needs to be kept still or moved a little as possible;

3) harmful aluminum bronze steam is generated in the welding process, the health of welders is harmed, and automatic welding is needed;

4) the traditional aluminum bronze surfacing process has high requirement on welding preheating temperature and directly influences the production efficiency;

5) the welding quality control of multilayer multi-pass welding is always a difficult problem of welding, and quantitative research on welding morphology and welding gun position is urgently needed;

the background needs an automatic pulse MIG (metal-inert gas) surfacing method for aluminum bronze on an upstream flange and a downstream flange, but the current aluminum bronze surfacing welding process is short of experience, and the multilayer multi-channel automatic pulse MIG surfacing of the aluminum bronze does not have related manufacturing experience in China.

The invention content is as follows:

the invention aims to provide an automatic pulse MIG (metal-inert gas) surfacing method for aluminum bronze on an upstream flange and a downstream flange, which can be used for obtaining weld joint forming with consistent height, width and width through a reasonable teaching means and a welding manufacturing process, avoiding the defects of incomplete welding, pores and the like and improving the welding quality of workpieces. The technical scheme of the invention is as follows:

1) the upstream flange and the downstream flange are fixed on the buttress, and a flip-chip welding robot is suspended to carry out surfacing welding on the upstream flange and the downstream flange;

2) teaching a welding robot aiming at a first welding seam of the upstream and downstream flanges, wherein the teaching track is circular, and the teaching points comprise four intersection points of an X axis of an absolute coordinate system and a Y axis of the absolute coordinate system of the welding robot and the upstream and downstream flanges; adjusting the distance and the angle between a welding gun nozzle of the welding robot and the surfacing surfaces of the upstream flange and the downstream flange by using the coordinate parameters fed back on a display screen of a demonstrator, wherein the minimum distance between the welding gun nozzle and the surfacing surfaces of the upstream flange and the downstream flange is 12-16 mm, the angle between the welding gun nozzle and the welding direction is 95-105 degrees, and the downward inclination angle of the welding gun nozzle in the horizontal direction is 30-45 degrees;

3) and setting the offset size of the welding seam and the angle of a welding gun by taking the first bottoming welding seam as a standard, and obtaining the surfacing welding seams of the upstream and downstream flanges except the first bottoming welding seam. The offset of the welding line in the vertical direction is 4-6 mm, and the offset of the welding line in the horizontal direction is 5-7 mm; for the second welding seam, the angle between the nozzle of the welding gun and the welding direction is 95-105 degrees, and the downward inclination angle of the nozzle of the welding gun in the horizontal direction is 30-45 degrees; for the surfacing welding seams except for the first bottoming welding seam and the second bottoming welding seam, the angle between a welding gun nozzle and the welding direction is 95-105 degrees, and the downward inclination angle of the welding gun nozzle in the horizontal direction is 5-20 degrees;

4) formal welding: the welding wire is an ERCuAl-A2 welding wire, the protective gas is Ar with the purity more than or equal to 99.99 percent, the gas flow is 20L/min-23L/min, the preheating temperature is not less than 16 ℃, the interlayer temperature is not more than 150 ℃, and a pulse MIG welding method is adopted: the welding process parameters are as follows: the current is 230A-270A, the voltage is 25V-28V, the arc length is corrected by + 3% -10%, and the welding speed is 25 cm/min-40 cm/min.

The technical effects are as follows:

the invention can automatically pulse MIG bead weld the aluminum bronze to the upstream and downstream flanges, and has the following technical advantages:

1) the process method used by the invention has stable quality in the welding process, is not influenced by human factors, and greatly improves the PT flaw detection qualification rate after the aluminum bronze welding seam is processed; the robot welding can strictly execute operation according to preset process specifications, accurately control the welding seam fusion ratio, ensure that the hardness is not lower than 130HB, and meet the wear-resistant requirement;

2) the process method used by the invention does not need a positioner, only uses the buttress with lower cost, greatly reduces the manufacturing cost, and greatly enhances the universality of the process method;

3) the process method used by the invention uses the robot to automatically weld, so that the operator can be far away from the toxic environment, and the body health of the operator is protected;

4) the process method adopted by the invention adopts pulse MIG welding, can concentrate the energy of the electric arc, has strong impact force of the electric arc, thus the preheating temperature is lower, the production time is shortened, and the service life of the robot is prolonged;

5) the welding process method used by the invention realizes controllable robot automatic multilayer multi-pass welding by weld seam quantitative measurement and welding shrinkage measurement;

6) according to the teaching mode used by the invention, four intersection points of X, Y axes and the upstream and downstream flanges (1) in an absolute coordinate system of the welding robot (2) are selected as circular track teaching points at the position where the central axis (4) of the first axis of the welding robot coincides with the axes of the upstream and downstream flanges (1), at the moment, the demonstrator can intuitively and accurately reflect the included angle between the welding gun nozzle (3) and the circular teaching track, the angle of the welding gun nozzle (3) can be controlled to be consistent relative to the tangential direction of the circular track teaching points, and the influence of accumulated deviation of multilayer multi-pass welding angles on the welding quality of subsequent welding seams is avoided.

The invention is an innovation of the traditional welding method, has strong welding operability, reduces the cost and the dependence on the tool, and ensures that the welding quality meets the design requirement.

Description of the drawings:

FIG. 1 is a schematic diagram of automatic pulse MIG surfacing of aluminum bronze on upstream and downstream flanges

FIG. 2 is a schematic view of the weld overlay of upstream and downstream flanges

In the drawings:

1 upstream and downstream flange 2 welding robot

3 welding gun nozzle 4 welding robot first shaft central axis

5 buttress 6 absolute coordinate system X-axis

7 absolute coordinate system Y-axis 8 backing first weld

9 backing second weld

The specific implementation mode is as follows:

the invention provides a process method for automatically pulse MIG surfacing welding of aluminum bronze on an upstream flange and a downstream flange, which comprises the following specific embodiments according to the technical scheme provided by the invention:

1) as shown in fig. 1, the upstream and downstream flanges 1 are leveled and leveled: hanging the upstream and downstream flanges 1 on the buttress 5, and leveling by using a level meter to ensure that the levelness of the upstream and downstream flanges 1 is +/-2 mm; adjusting the position of the robot to ensure that the central axis 4 of the first shaft of the welding robot coincides with the axes of the upstream flange 1 and the downstream flange 1, and the coaxiality is +/-5 mm;

2) teaching a welding robot 2 aiming at a first welding seam 8 of the upstream flange and the downstream flange 1, wherein the teaching track is circular, and teaching points comprise four intersection points of an X axis 6 of an absolute coordinate system and a Y axis 7 of the absolute coordinate system of the welding robot 2 and the upstream flange and the downstream flange 1; adjusting the distance and angle between a welding gun nozzle 3 of the welding robot and the surfacing surfaces of the upstream and downstream flanges 1 according to the X, Y, Z value and the alpha, beta and gamma space angle values of a teaching panel, wherein the minimum distance between the welding gun nozzle 3 and the surfacing surfaces of the upstream and downstream flanges 1 is 12-16 mm, the angle between the welding gun nozzle 3 and the welding direction is 95-105 degrees, and the downward inclination angle of the welding gun nozzle 3 in the horizontal direction is 30-45 degrees;

3) and setting the offset size of the welding seam and the angle of a welding gun by taking the taught priming first welding seam 8 as a reference to obtain the surfacing welding seams of the upstream and downstream flanges 1 except the priming first welding seam 8. The offset of the welding line in the vertical direction is 4-6 mm, and the offset of the welding line in the horizontal direction is 5-7 mm; for the bottoming second welding seam 9, the angle between the welding gun nozzle 3 and the welding direction is 95-105 degrees, and the downward inclination angle of the welding gun nozzle 3 in the horizontal direction is 30-45 degrees; for the surfacing welding seams except the first bottoming welding seam 8 and the second bottoming welding seam 9, the angle between the welding gun nozzle 3 and the welding direction is 95-105 degrees, and the downward inclination angle of the welding gun nozzle 3 in the horizontal direction is 5-20 degrees;

4) formal welding: the welding wire is an ERCuAl-A2 welding wire, the protective gas is Ar with the purity of more than or equal to 99.99 percent, the gas flow is 20L/min to 23L/min, the preheating temperature is not less than 16 ℃, the interlayer temperature is not more than 150 ℃, a pulse MIG welding method is adopted, and the welding technological parameters are as follows: the current is 230A-270A, the voltage is 25V-28V, the arc length is corrected by + 3% -10%, and the welding speed is 25 cm/min-40 cm/min.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the claims and their equivalents.

Claims (1)

1. An automatic pulse MIG (metal-inert gas) surfacing method for upstream and downstream flanges is characterized by comprising the following steps of: the method comprises the following steps:

1) the upstream and downstream flanges (1) are fixed on the buttress (5), and a flip-chip welding robot (2) is suspended to carry out surfacing welding on the upstream and downstream flanges (1);

2) teaching a welding robot (2) aiming at a first bottoming welding seam (8) of an upstream flange and a downstream flange (1), wherein a teaching track is circular, teaching points comprise four intersection points of an X axis (6) of an absolute coordinate system and a Y axis (7) of the absolute coordinate system of the welding robot (2) and the upstream flange and the downstream flange (1), and the distance and the angle between a welding gun nozzle (3) of the welding robot and the surfacing surfaces of the upstream flange and the downstream flange (1) are adjusted by utilizing coordinate parameters fed back on a display screen of a demonstrator, wherein the minimum distance between the welding gun nozzle (3) and the surfacing surfaces of the upstream flange and the downstream flange (1) is 12-16 mm, the angle between the welding gun nozzle (3) and the welding direction is 95-105 degrees, and the downward inclination angle of the welding gun nozzle (3) in the horizontal direction is 30-45 degrees;

3) setting the offset size and the welding gun angle of a welding seam by taking a taught priming first welding seam (8) as a reference to obtain surfacing welding seams of the upstream and downstream flanges (1) except the priming first welding seam (8), wherein the offset of the welding seam in the vertical direction is 4-6 mm, and the offset of the welding seam in the horizontal direction is 5-7 mm; for the bottoming second welding seam (9), the angle between the welding gun nozzle (3) and the welding direction is 95-105 degrees, and the downward inclination angle of the welding gun nozzle (3) in the horizontal direction is 30-45 degrees; for the surfacing welding seams except for the first bottoming welding seam (8) and the second bottoming welding seam (9), the angle between the welding gun nozzle (3) and the welding direction is 95-105 degrees, and the downward inclination angle of the welding gun nozzle (3) in the horizontal direction is 5-20 degrees;

4) formal welding: the welding wire is an ERCuAl-A2 welding wire, the protective gas is Ar with the purity more than or equal to 99.99 percent, the gas flow is 20L/min-23L/min, the preheating temperature is not less than 16 ℃, the interlayer temperature is not more than 150 ℃, and a pulse MIG welding method is adopted: the welding process parameters are as follows: the current is 230A-270A, the voltage is 25V-28V, the arc length is corrected by + 3% -10%, and the welding speed is 25 cm/min-40 cm/min.

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