CN111408895A - Large-gap argon arc welding back cover repairing method for carbon steel pipeline and container - Google Patents
Large-gap argon arc welding back cover repairing method for carbon steel pipeline and container Download PDFInfo
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- CN111408895A CN111408895A CN202010389553.6A CN202010389553A CN111408895A CN 111408895 A CN111408895 A CN 111408895A CN 202010389553 A CN202010389553 A CN 202010389553A CN 111408895 A CN111408895 A CN 111408895A
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- 238000003466 welding Methods 0.000 title claims abstract description 320
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 title claims abstract description 72
- 229910052786 argon Inorganic materials 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 28
- 229910000975 Carbon steel Inorganic materials 0.000 title claims abstract description 16
- 239000010962 carbon steel Substances 0.000 title claims abstract description 16
- 230000007547 defect Effects 0.000 claims abstract description 39
- 238000007789 sealing Methods 0.000 claims abstract description 16
- 238000010438 heat treatment Methods 0.000 claims abstract description 12
- 230000035515 penetration Effects 0.000 claims abstract description 12
- 238000001514 detection method Methods 0.000 claims abstract description 10
- 238000010891 electric arc Methods 0.000 claims abstract description 9
- 238000009659 non-destructive testing Methods 0.000 claims abstract description 7
- 239000011324 bead Substances 0.000 claims description 114
- 239000000463 material Substances 0.000 claims description 9
- 239000010953 base metal Substances 0.000 claims description 6
- 238000007689 inspection Methods 0.000 claims description 6
- 239000002893 slag Substances 0.000 claims description 6
- 238000004140 cleaning Methods 0.000 claims description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 3
- 238000002844 melting Methods 0.000 claims description 3
- 230000008018 melting Effects 0.000 claims description 3
- 238000005498 polishing Methods 0.000 claims description 3
- 238000003303 reheating Methods 0.000 claims description 3
- 238000007778 shielded metal arc welding Methods 0.000 claims description 3
- 230000007704 transition Effects 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 230000004927 fusion Effects 0.000 abstract description 5
- 230000002035 prolonged effect Effects 0.000 abstract 1
- 239000002184 metal Substances 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 239000010410 layer Substances 0.000 description 7
- 229910000831 Steel Inorganic materials 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000011229 interlayer Substances 0.000 description 2
- NGONBPOYDYSZDR-UHFFFAOYSA-N [Ar].[W] Chemical compound [Ar].[W] NGONBPOYDYSZDR-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P6/00—Restoring or reconditioning objects
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K33/00—Specially-profiled edge portions of workpieces for making soldering or welding connections; Filling the seams formed thereby
- B23K33/004—Filling of continuous seams
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/02—Seam welding; Backing means; Inserts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/16—Arc welding or cutting making use of shielding gas
- B23K9/167—Arc welding or cutting making use of shielding gas and of a non-consumable electrode
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Abstract
The invention discloses a large-gap argon arc welding back cover repairing method for carbon steel pipelines and containers, which comprises the following steps of: positioning welding defects, repairing defects, grinding and repairing a groove, performing penetration flaw detection on the groove, fixing a welding seam, preheating before welding, sealing bottom observation in argon arc welding, filling welding rod arc welding, capping, performing heat treatment after welding and performing nondestructive testing. The welding process combines two different welding methods of argon arc welding and manual electric arc welding, and a special welding bottom sealing mode is used, so that even if a large-gap welding seam at the root of a pipeline and a container which are extremely difficult to treat in welding repair is faced, a high-quality welding seam can be obtained, and due to the fact that a metallographic structure is fine, the impact toughness of the welding seam, a fusion zone and a heat affected zone is high, the crack tendency is small, and the service life of a welding joint is prolonged.
Description
Technical Field
The invention relates to a large-gap argon arc welding bottom sealing process, which is suitable for the field of pipeline and container welding and the like, in particular to a large-gap argon arc welding bottom sealing repairing method for carbon steel pipelines and containers.
Technical Field
When the carbon steel pipeline and the container are constructed and installed, due to assembly errors, the phenomenon of gap super-difference sometimes occurs, so that the root gap is enlarged; after welding of the welding seams of the carbon steel pipeline and the container, the root is detected to have an overproof defect, the repair is carried out, and the gap between the roots is often wider.
When the large-gap argon arc welding back cover welding of the penetration defect of the carbon steel and the container pipeline is carried out, the swinging welding is generally carried out by taking two sides of the root part of the groove as base points, the molten pool is wide and thick, the volume is large, the high-temperature time is long, the crystal grains of a welding line and a heat affected zone are thick, the plasticity and the toughness are poor, and cracks are easy to generate; the back of the upper part of the welding seam is easy to form welding beading, the back of the lower part of the welding seam is easy to form concave, and the sudden change of the geometrical shape of the inner wall has adverse effect on the flow of an internal medium.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a method for repairing the large-gap argon arc welding back cover and the welding rod arc welding filling cover surface of the penetration defect of the carbon steel pipeline and the container, which can obtain excellent mechanical property and prolong the service life of equipment on the premise of ensuring that no welding defect exists in the welding seam.
The technical scheme of the invention is realized as follows:
a large-gap argon arc welding back cover repairing method for carbon steel pipelines and containers comprises the following steps:
step 1: positioning welding defects: and determining the properties, depth, length, width and trend of the pipeline defects in a nondestructive testing mode, and positioning, identifying and recording the appearance.
Step 2: defect cleaning: and aiming at the position, the property and the size of the defect, a carbon arc gouging or cutting and polishing mode is selected, and the position of the defect is found by digging from the outside to the inside of the outer surface of the pipeline.
And step 3: grinding of groove: after digging to the defect position, grinding the shape of the groove to ensure that the groove surface has no larger edge angle; if the defect penetrates through the pipe wall, the bevel angles at the two sides are ground into 120~150And the truncated edge is 0.5-1mm, and burrs and oxides on the inner surface are cleaned.
And 4, step 4: and (3) performing penetration flaw detection on the groove: and (4) performing penetration flaw detection on the surface of the groove according to the reference record, and observing the inner surface of the pipeline by using an endoscope if the size of the penetration defect is large, so as to ensure that the defect is cleaned completely.
And 5: preheating before welding: and (3) preheating the welding line before welding by adopting infrared heating or gas flame at the temperature of 100-.
Step 6: argon arc welding bottom sealing: for the argon arc welding back cover for the pipe horizontal fixed welding with the oversized root gap, after the argon arc welding back cover for the oversized root gap of the horizontal fixed pipe is completed, manual welding filling and capping are carried out; and (3) vertically fixing and welding the tube with the oversized root gap, and sealing the bottom by using argon arc welding, and filling and capping by manual welding after completing the argon arc welding of the oversized root gap of the vertically fixed tube.
And 7: welding rod arc welding filling: and (3) adopting multilayer multi-pass welding, carrying out backing welding in the same welding sequence and direction, after arc striking is carried out at a position 10mm away from the front of the initial welding end of the welding seam, rapidly moving the electric arc to the initial welding end for welding, cleaning up slag of the welding bead, lowering the height of the filling welding layer by 1-1.5mm compared with the surface of the base metal, and reserving the edge of a groove so as to facilitate the cover surface.
And 8: shielded metal arc welding facing: and adopting multilayer multi-pass welding, wherein an arc striking method is the same as that of the filling layer, the edge of the melting groove is 1-2mm, the welding seam edge and the lower layer are well fused during capping, and the welding seam edge and the base metal are in smooth transition.
And step 9: nondestructive testing: and carrying out nondestructive flaw detection on the welding seam to ensure that the welding seam has no standard exceeding defect.
Step 10: postweld heat treatment: and after welding, slowly and uniformly heating the welding line to 550-650 ℃, preserving heat for 30-60 min, and then slowly cooling.
Step 11: nondestructive inspection rechecking: and performing nondestructive inspection and rechecking on the material with temper brittleness or reheating crack tendency after postweld heat treatment.
According to the invention, welding deformation is reduced by adopting fixed welding seams, a groove with a larger volume after digging the groove needs to be welded and fixed by a rigid block, the depth of the rigid block embedded into the groove is 10-15mm, so that backing welding is not hindered, and the material of the rigid block and the welding material are matched with a welding process and a pipeline. And during formal welding, the welding material is matched with the welding process card. The welding current, the arc voltage and the welding speed are adjusted, the welding heat input is controlled, welding is carried out in a large-gap state, and good back molding is obtained. The welding process is single-sided multilayer multi-pass welding, the interlayer temperature is 100-200 ℃, and the joints are staggered by 30 mm. The root part adopts manual argon tungsten-arc welding and direct current direct connection, the filling cover surface adopts manual electric arc welding and direct current reverse connection. For an oversized root gap, overlaying welding is carried out on the lower side slope root metal along the length direction of the groove by taking the groove root metals on two sides as base points, one backing welding (one backing welding) is needed every two overlaying welding operations, the thickness of a weld joint near the groove side is increased, and welding beading is prevented from being generated due to overhigh temperature; the horizontal fixed pipe is folded from the two sides of the groove to the middle, and the vertical fixed pipe is folded from the downward groove to the upward groove until the gap at the root of the groove is filled.
The invention has the beneficial effects that: the special argon arc welding bottom sealing mode is adopted, manual electric arc welding filling and cover surface are matched, even if large-gap welding seams at the root parts of pipelines and containers which are extremely difficult to treat in welding repair are faced, high-quality welding seams can be obtained, welding beading at the root parts of the welding seams is avoided, stress concentration is reduced, the metallographic structure is fine, the impact toughness of the welding seams, a fusion zone and a heat affected zone is high, the crack tendency is small, and the mechanical property is good.
Drawings
FIG. 1 is a bevel view of the welding process of the present invention.
FIG. 2 is a sequence diagram of groove welding of horizontal stationary pipes used in the welding process of the present invention.
FIG. 3 is a sequence diagram of groove welding of a vertical fixed pipe used in the welding process of the present invention.
Detailed Description
The following further describes the embodiments with reference to the drawings.
As shown in the figure, the first and second,
step 1: positioning welding defects: and determining the properties, depth, length, width and trend of the pipeline defects (slag inclusion, non-fusion, cracks, incomplete penetration and pores) in a nondestructive testing mode, and positioning, identifying and recording the appearance.
Step 2: defect cleaning: and aiming at the position, the property and the size of the defect, selecting a carbon arc gouging or cutting and polishing mode, excavating from the outside and the inside of the outer surface of the pipeline, and observing and measuring in time along with the increase of the excavating thickness until the position of the defect is found. For metals with a large hardening tendency, preheating is needed during carbon arc gouging to prevent new defects from being generated.
And step 3: grinding the groove: after digging to the defect position, grinding the shape of the groove to ensure that the groove surface has no larger edge angle; if the defect penetrates through the pipe wall, the bevel angles at the two sides are ground into 12-15 degrees, the argon arc welding is convenient to operate, the truncated edge is 0.5-1mm, and burrs and oxides on the inner surface are cleaned.
And 4, step 4: performing penetration flaw detection on the groove and observing the inner surface; and (4) performing penetration flaw detection on the surface of the groove according to the reference record, if the size of the penetrating defect is large, digging to form a large gap, observing the inner surface of the pipeline by using an endoscope, and ensuring that the defect is cleaned completely.
And 5: preheating before welding: and (3) preheating the welding seam before welding by adopting infrared heating or gas flame at the temperature of 100-.
Step 6: argon arc welding bottom sealing (A tube is horizontally fixed, B tube is vertically fixed).
A. And for the horizontal fixed welding of the pipe with the oversized root gap, sealing the bottom by argon arc welding.
(1) Taking the metal at the root part of the groove as a base point, carrying out bead 1 surfacing vertically upwards along the length of the groove, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 10-12 cm/min.
(2) And (3) performing bead surfacing on the weld bead 2 by taking the weld bead 1 and the bevel edge as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(3) And (3) performing bead 3 surfacing by taking the weld bead 1 and the weld bead 2 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 10-12 cm/min.
(4) And (3) performing weld bead 4 surfacing towards the upper part of the pipeline along the length of the groove by taking the metal at the root part of the groove as a base point, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 10-12 cm/min.
(5) And (3) performing bead 5 surfacing by taking the bead 4 and the bevel edge as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(6) And (3) performing bead build-up welding on a weld bead 6 by taking the weld bead 4 and the bevel edge as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 10-12 cm/min.
(7) And (3) performing bead 7 surfacing by taking the bead 2 as a base point, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(8) And (3) performing bead 8 surfacing by taking the weld bead 2, the weld bead 3 and the weld bead 7 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-.
(9) And (3) performing bead 9 surfacing by taking the bevel edge, the weld bead 3 and the weld bead 8 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 10-12 cm/min.
(10) And (3) performing bead 10 surfacing by taking the bead 5 as a base point, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(11) And (3) performing bead 11 surfacing by taking the weld bead 5, the weld bead 6 and the weld bead 10 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-.
(12) And (3) performing bead 12 surfacing by taking the bevel edge, the weld bead 6 and the weld bead 11 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 10-12 cm/min.
(13) And (3) performing bead surfacing by taking the weld bead 7 as a base point, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(14) And (3) performing bead 14 surfacing by taking the weld bead 7, the weld bead 8 and the weld bead 13 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-.
(15) And (3) performing bead 15 surfacing by taking the weld bead 10 as a base point, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(16) And (3) performing bead 16 surfacing by taking the weld bead 10, the weld bead 11 and the weld bead 15 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-.
(17) And (3) performing bead 17 surfacing by taking the weld bead 8, the weld bead 9 and the weld bead 14 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-.
(18) Bead 18 is built up by taking the weld bead 11, the weld bead 12 and the weld bead 16 as base points, the diameter of a welding wire is ø 2.4.4 mm, the current is 100-.
(19) And (3) taking the welding bead 13 and the welding bead 15 as base points, carrying out the folding welding of the welding bead 19, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-.
(19) Welding bead 20 is carried out by taking the welding bead 13, the welding bead 15 and the welding bead 19 as base points, the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
So far, the argon arc welding back cover of the oversized root gap of the horizontal fixed pipe is completed, and manual welding filling and cover face can be carried out.
B. Vertical fixation:
for the vertical fixed welding of the pipe with the oversized root gap, the bottom sealing is performed by argon arc welding:
(1) and (3) performing weld bead 1 transverse overlaying on the pipeline along the length of the groove by taking the metal at the root part of the groove as a base point, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(2) And (3) performing transverse overlaying welding on a welding bead 2 by taking the welding bead 1 and the bevel edge as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(3) And (3) performing transverse overlaying welding of a welding bead 3 by taking the welding bead 2 and the bevel edge as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(4) And (3) performing weld bead 4 transverse overlaying by taking the weld bead 1 and the weld bead 2 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(5) And (3) performing transverse overlaying of a weld bead 5 by taking the weld bead 2 and the weld bead 4 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(6) And (3) using the welding bead 3 and the welding bead 5 as base points, performing transverse overlaying welding on the welding bead 6, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(7) And (3) performing weld bead 7 transverse overlaying by taking the weld bead 4 and the weld bead 5 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(8) And (3) performing transverse overlaying of a weld bead 8 by taking the weld bead 5 and the weld bead 7 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(9) And (3) performing transverse overlaying of a weld bead 9 by taking the weld bead 6 and the weld bead 8 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(10) Using the welding bead 7 and the welding bead 8 as base points to carry out the transverse overlaying welding of the welding bead 10, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(11) Using the welding bead 8 and the welding bead 10 as base points to carry out the transverse overlaying welding of the welding bead 11, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(12) Using the welding bead 9 and the welding bead 11 as base points to carry out the transverse overlaying welding of the welding bead 12, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(13) Using the welding bead 10 and the welding bead 11 as base points to carry out the transverse overlaying welding of the welding bead 13, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(14) Using the welding bead 11 and the welding bead 13 as base points, performing welding bead 14 transverse overlaying, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(15) Using the welding bead 12 and the welding bead 14 as base points to carry out the transverse overlaying welding of the welding bead 15, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(16) And (3) performing weld bead 16 transverse overlaying by taking the weld bead 13 and the weld bead 14 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(17) And (3) performing transverse overlaying on the weld bead 17 by taking the weld bead 15 and the weld bead 16 as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(18) And (3) performing transverse overlaying of the welding bead 18 by taking the welding bead 116, the welding bead 17 and the upper groove root as base points, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
(19) Using the welding bead 17, the welding bead 18 and the bevel edge as base points to carry out the transverse overlaying of the welding bead 19, wherein the diameter of a welding wire is ø 2.4.4 mm, the current is 100-120A, the voltage is 12-14V, and the welding speed is 12-14 cm/min.
So far, the argon arc welding back cover of the oversized root gap of the vertical fixed pipe is completed, and manual welding filling and cover face can be carried out.
And 7, welding rod arc welding filling, namely adopting multilayer multi-pass welding, carrying out backing welding in sequence and direction, rapidly moving the electric arc to the initial welding end for welding after the electric arc is ignited at a position 10mm away from the front of the initial welding end of the welding seam, avoiding generating defects, cleaning slag of the welding bead in time, facilitating the fusion and slag discharge of the welding rod, preventing the welding seam from being unfused and slag inclusion, keeping the edge of the groove and facilitating the cover surface, wherein the height of the filling welding layer is 1-1.5mm lower than the surface of the base metal.
According to the method for repairing the large-gap argon arc welding back cover of the carbon steel pipeline and the container, welding deformation is reduced by adopting welding seam fixation, a groove with a larger volume after digging the groove needs to be welded and fixed by a rigid block, the depth of the rigid block embedded into the groove is 10-15mm, backing welding is not influenced, and the material of the rigid block and the welding material are matched with the pipeline in the welding process.
According to the large-gap argon arc welding back cover repairing method for the carbon steel pipeline and the container, during formal welding, welding materials are matched with the welding process card.
According to the method for repairing the large-gap argon arc welding back cover of the carbon steel pipeline and the container, welding heat input is controlled by adjusting welding current, arc voltage and welding speed, welding is carried out in a large-gap state, and good back forming is obtained.
According to the large-gap argon arc welding bottom sealing repair method for the carbon steel pipeline and the container, the welding process is single-side multi-layer multi-pass welding, the interlayer temperature is 100 ℃ and 200 ℃, and the joints are staggered by 30 mm.
The large-gap argon arc welding bottom sealing repair method for the carbon steel pipeline and the container is characterized in that manual tungsten argon arc welding and direct current direct connection are adopted at the root part, manual electric arc welding is adopted for filling the cover surface, and direct current reverse connection is adopted.
The large-gap argon arc welding bottom sealing repair method for the carbon steel pipeline and the container is characterized in that for an oversized root gap, overlaying welding is carried out on the lower side groove root metal along the length direction of the groove by taking the groove root metals on two sides as base points, and one backing weld (two advancing and one backing weld) is needed to be carried out every two overlaying welds, so that the thickness of a near-groove side weld is increased, and welding beading is prevented from being generated due to overhigh temperature; the horizontal fixed pipe is folded from the two sides of the groove to the middle, and the vertical fixed pipe is folded from the downward groove to the upward groove until the gap at the root of the groove is filled.
Aiming at the defects of the prior art, the invention adopts a special argon arc welding bottom sealing mode and is matched with manual electric arc welding filling and capping, even if the welding seam with large clearance at the root of a pipeline and a container which are extremely difficult to treat in welding repair is faced, a high-quality welding seam can be obtained, the generation of welding beading at the root of the welding seam is avoided, the stress concentration is reduced, the metallographic structure is fine, and the impact toughness of the welding seam, a fusion zone and a heat affected zone is high, the crack tendency is small, and the mechanical property is good.
Claims (1)
1. A large-gap argon arc welding back cover repairing method for carbon steel pipelines and containers is characterized by comprising the following steps:
step 1: positioning welding defects: determining the properties, depth, length, width and trend of the pipeline defects in a nondestructive testing mode, and positioning, identifying and recording the appearance of the pipeline defects;
step 2: defect cleaning: aiming at the position, the property and the size of the defect, a carbon arc gouging or cutting and polishing mode is selected, and the position of the defect is found by digging from the outside and the inside of the outer surface of the pipeline;
and step 3: grinding the groove: after digging to the defect position, grinding the shape of the groove to ensure that the groove surface has no larger edge angle; if the defect penetrates through the pipe wall, the bevel angles at the two sides are ground into 120~150The truncated edge is 0.5-1mm, and burrs and oxides on the inner surface are cleaned;
and 4, step 4: and (3) performing penetration flaw detection on the groove: performing penetration flaw detection on the surface of the groove by referring to the record, and observing the inner surface of the pipeline by using an endoscope if the volume of the penetration flaw is large to ensure that the flaw is cleaned;
and 5: preheating before welding: preheating a welding line before welding by adopting infrared heating or gas flame at the temperature of 100-;
step 6: argon arc welding bottom sealing: for the argon arc welding back cover for the pipe horizontal fixed welding with the oversized root gap, after the argon arc welding back cover for the oversized root gap of the horizontal fixed pipe is completed, manual welding filling and capping are carried out; vertically and fixedly welding the tube with the oversized root gap and sealing the bottom by argon arc welding, and filling and capping by manual welding after completing the argon arc welding of the oversized root gap of the vertically fixed tube;
and 7: welding rod arc welding filling: multilayer multi-pass welding is adopted, the welding sequence and the welding direction are the same as that of backing welding, after arc striking is carried out at a position 10mm away from the front of the initial welding end of a welding seam, the electric arc is rapidly moved to the initial welding end for welding, slag of the welding bead is cleaned, the height of a filling welding layer is 1-1.5mm lower than that of the surface of a base metal, and the edge of a groove is reserved so as to facilitate the cover surface;
and 8: shielded metal arc welding facing: adopting multilayer multi-pass welding, wherein an arc striking method is the same as that of a filling layer, the edge of a melting groove is 1-2mm, the edge of a welding seam and a lower layer are well fused when the surface is covered, and the edge of the welding seam and a base metal are in smooth transition;
and step 9: nondestructive testing: carrying out nondestructive flaw detection on the welding seam to ensure that the welding seam has no standard exceeding defect;
step 10: postweld heat treatment: after welding, slowly and uniformly heating the welding line to 550-650 ℃, preserving heat for 30-60 min, and then slowly cooling;
step 11: nondestructive inspection rechecking: and performing nondestructive inspection and rechecking on the material with temper brittleness or reheating crack tendency after postweld heat treatment.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111906414A (en) * | 2020-07-08 | 2020-11-10 | 湖南华菱湘潭钢铁有限公司 | Large-gap multilayer stepping argon arc welding back cover repairing method for carbon steel pipeline and container |
| CN112439972A (en) * | 2020-09-29 | 2021-03-05 | 上海江南长兴造船有限责任公司 | Welding method for solving out-of-tolerance problem of crack arrest steel butt welding groove gap |
| CN113172310A (en) * | 2021-04-16 | 2021-07-27 | 哈尔滨焊接研究院有限公司 | Welding process for inlet and outlet connecting pipe of low-temperature reactor pressure vessel and heat exchanger connecting pipe |
| CN115386873A (en) * | 2022-09-06 | 2022-11-25 | 北京航星机器制造有限公司 | Defect repairing method for TA15 titanium alloy part formed by selective laser melting |
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- 2020-05-10 CN CN202010389553.6A patent/CN111408895A/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111906414A (en) * | 2020-07-08 | 2020-11-10 | 湖南华菱湘潭钢铁有限公司 | Large-gap multilayer stepping argon arc welding back cover repairing method for carbon steel pipeline and container |
| CN111906414B (en) * | 2020-07-08 | 2022-03-01 | 湖南华菱湘潭钢铁有限公司 | Large-gap multilayer stepping argon arc welding back cover repairing method for carbon steel pipeline and container |
| CN112439972A (en) * | 2020-09-29 | 2021-03-05 | 上海江南长兴造船有限责任公司 | Welding method for solving out-of-tolerance problem of crack arrest steel butt welding groove gap |
| CN113172310A (en) * | 2021-04-16 | 2021-07-27 | 哈尔滨焊接研究院有限公司 | Welding process for inlet and outlet connecting pipe of low-temperature reactor pressure vessel and heat exchanger connecting pipe |
| CN115386873A (en) * | 2022-09-06 | 2022-11-25 | 北京航星机器制造有限公司 | Defect repairing method for TA15 titanium alloy part formed by selective laser melting |
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