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CN-121988834-A - Argon arc welding seam welding method for lock bottom butt joint with thermal barrier coating

CN121988834ACN 121988834 ACN121988834 ACN 121988834ACN-121988834-A

Abstract

The application relates to an argon arc welding seam welding method of a lock bottom butt joint with a thermal barrier coating, which comprises the following steps of S1, processing a weld joint, namely processing a first groove on a lock bottom at the installation edge of the inner wall of a large bent pipe to be welded, reserving a blunt edge, processing a second groove at the installation edge of the outer wall of the large bent pipe, reserving the blunt edge, combining the inner wall of the large bent pipe with the installation edge of the outer wall of the large bent pipe, aligning the lock bottom of the inner wall of the large bent pipe with the installation edge of the outer wall of the large bent pipe, enabling a gap at the to-be-welded position to be smaller than or equal to a first threshold value, S2, performing first-layer priming welding, directly penetrating the blunt edge without filling welding wires during welding, and performing step S3 after waiting for cooling, performing second-layer capping welding, and filling welding wires at the first groove and the second groove. The application not only can ensure the welding quality, but also can obviously reduce the heat input during welding and effectively avoid the falling of the coating, thereby prolonging the service life of the large bent pipe of the aeroengine.

Inventors

  • ZHANG MI
  • XIN KAI
  • HE HONGLIANG
  • CHEN LIANG
  • Wan Lianjin
  • ZHANG KUN
  • SHI FANG

Assignees

  • 中国航发南方工业有限公司

Dates

Publication Date
20260508
Application Date
20260325

Claims (10)

  1. 1. The argon arc welding method of the lock bottom butt joint with the thermal barrier coating is characterized by comprising the following steps of: S1, processing a welding joint, namely processing a first groove (12) on a lock bottom (11) at the installation edge of the inner wall (1) of the large elbow to be welded, reserving a first blunt edge (13), processing a second groove (22) at the installation edge of the outer wall (2) of the large elbow, and reserving a second blunt edge (23), combining the inner wall (1) of the large elbow with the outer wall (2) of the large elbow, aligning the lock bottom (11) of the inner wall (1) of the large elbow with the installation edge of the outer wall (2) of the large elbow, and enabling the gap at the position to be welded to be smaller than or equal to a first threshold value; S2, performing first layer priming welding, directly penetrating through the second blunt edge (23) and the first blunt edge (13) without filling welding wires during welding, and performing step S3 after cooling; S3, performing second-layer cover surface welding, filling welding wires into the first groove (12) and the second groove (22), and then performing welding.
  2. 2. The argon arc welding method for the lock bottom butt joint with the thermal barrier coating, which is characterized by adopting a welding current lower than 53A and a welding speed higher than 3mm/s under the condition of ensuring that a welding seam can be thoroughly welded when the first layer of backing welding is carried out, and adopting a welding current lower than 57A and a welding speed lower than 5mm/s under the condition of ensuring that filling of a welding groove is full and internal defects are not caused when the second layer of facing welding is carried out.
  3. 3. The argon arc welding method for the lock bottom butt joint with the thermal barrier coating according to claim 1, wherein in the step S2, the welding current is 45-52A, the welding speed is 4-7 mm/S, and the argon flow is 9-11L/min.
  4. 4. The argon arc welding method for the lock bottom butt joint with the thermal barrier coating according to claim 1, wherein in the step S3, the welding current is 52-57A, the welding speed is 2-4 mm/S, and the argon flow is 9-11L/min.
  5. 5. The argon arc welding method for the butt joint of the lock bottom with the thermal barrier coating according to claim 1, wherein the inclination angle of the first groove (12) is 43-47 degrees, the depth is 0.7-0.8 mm, and the thickness of the first blunt edge (13) is 0.2-0.3 mm when the lock bottom (11) is processed.
  6. 6. The argon arc welding method for the lock bottom butt joint with the thermal barrier coating according to claim 1, wherein when the installation edge of the outer wall (2) of the large bent pipe is machined, the width of the second groove (22) is 1.2-1.3 mm, the depth is 0.7-0.8 mm, and the thickness of the second blunt edge (23) is 0.2-0.3 mm.
  7. 7. The argon arc welding method for a lock bottom butt joint with thermal barrier coating according to claim 1, wherein the first threshold value is 0.2mm.
  8. 8. The argon arc welding seam welding method of the lock bottom butt joint with the thermal barrier coating according to any one of claims 1 to 7, wherein a cooling circulation pipe (3) is adopted to cool a large bent pipe when welding is carried out in the step S1 and the step S2, and a circulating cooling medium is arranged in the cooling circulation pipe (3).
  9. 9. The argon arc welding method for the lock bottom butt joint with the thermal barrier coating according to claim 8, wherein the cooling circulation pipe (3) surrounds one side of the inner wall (1) of the large elbow with the thermal barrier coating (4).
  10. 10. The argon arc welding method for the lock bottom butt joint with the thermal barrier coating according to claim 9, wherein the cooling circulation pipe (3) is a copper pipe, the cross section of the copper pipe is flat, and one flat side is attached to one side of the inner wall (1) of the large elbow pipe with the thermal barrier coating (4).

Description

Argon arc welding seam welding method for lock bottom butt joint with thermal barrier coating Technical Field The application relates to the technical field of lock bottom butt joint weld joint welding, in particular to an argon arc welding seam welding method for a lock bottom butt joint with a thermal barrier coating. Background The two layers of wall surfaces of the large elbow of the aeroengine are formed by welding and combining locking bottom butt joints at the mounting edges of the inner wall and the outer wall, the workpiece material GH3044 is 3.4mm, the thickness of the mounting edge of the outer wall is 1mm, and the surface of the workpiece at one side of the inner wall is sprayed with a ZrO 2/Y2O3 ceramic thermal barrier coating. The butt joint of the lock bottom at the installation edge of the inner wall and the outer wall is welded by manual argon arc welding. When smaller heat input is adopted, the welding line cannot be welded thoroughly, the strength of the welding line is seriously reduced, and the internal incomplete welding defect can become a crack source to cause the welding line crack, so that the structural safety of the workpiece is seriously affected. In order to completely weld the welded joint, 70A current is required for welding, the welding speed is 2-3 mm/s, the filler wire HGH3044 is used, the welding heat input is large in the state, under the action of rapid heating and quenching in welding, the ceramic coating and the matrix metal simultaneously generate severe thermal expansion and contraction, but because the thermal expansion coefficient difference between the surface thermal barrier ceramic coating and the metal matrix is large, the expansion degree of the metal matrix is obviously larger than that of the ceramic coating, the ceramic coating cannot jointly expand and contract along with the matrix metal, so that the binding force of the ceramic coating and the matrix metal is reduced, the phenomena of coating cracking, falling off and the like occur, the phenomena are aggravated by excessive heat input, the heat bearing capacity of the large elbow in service is seriously influenced by the falling of the coating, the large elbow is easy to generate cracks in the service environment of high temperature and high pressure, and the service life of the large elbow is seriously shortened. Disclosure of Invention The invention aims to overcome the defects that a lock bottom butt joint with a thermal barrier coating is welded, low-energy cannot be welded thoroughly, and the coating is easy to fall off due to high-energy, and provides an argon arc welding seam welding method for the lock bottom butt joint with the thermal barrier coating, which not only can be welded thoroughly, but also can avoid the problem that the coating falls off. In order to solve the technical problems, the invention adopts the following technical scheme: the argon arc welding method for the lock bottom butt joint with the thermal barrier coating comprises the following steps: S1, processing a weld joint, namely processing a first groove on a lock bottom at the mounting edge of the inner wall of a large bent pipe to be welded, reserving a first blunt edge, processing a second groove at the mounting edge of the outer wall of the large bent pipe, reserving a second blunt edge, combining the inner wall of the large bent pipe with the outer wall of the large bent pipe, aligning the lock bottom of the inner wall of the large bent pipe with the mounting edge of the outer wall of the large bent pipe, and enabling the gap at the position to be welded to be smaller than or equal to a first threshold value; S2, performing first layer priming welding, directly penetrating through the second blunt edge and the first blunt edge without filling welding wires during welding, and performing step S3 after cooling; s3, performing second-layer cover surface welding, filling welding wires in the first groove and the second groove, and then performing welding. The argon arc welding method for the lock bottom butt joint with the thermal barrier coating comprises the steps of firstly processing a large elbow to be welded, processing a second bevel on an outer wall mounting edge which is only 1mm thick originally, reserving a second blunt edge, correspondingly processing a first bevel on a lock bottom at the inner wall mounting edge of the large elbow, reserving the first blunt edge, and then directly welding the second blunt edge and the first blunt edge through the first layer in a two-layer welding mode when the large elbow is welded, wherein the thicknesses of the two blunt edges are thinner than those of the original large elbow due to the fact that the bevel is formed, welding penetration can be achieved only by adopting lower welding current when the first layer is welded, the problem that the thermal barrier coating is heated and falls off due to high-energy welding is avoided, and filling and leveling the bevel when the