Method for assembling and welding extension section of large-size high-temperature alloy single-wall spray pipe

Abstract

The invention discloses an assembling and welding method of a large-size high-temperature alloy single-wall spray pipe extension section, which comprises the following steps of: sequentially carrying out gas-shielded positioned welding and laser tailored welding on butt welding seams of all scalloped segments by using a positioned welding process device; edge rolling is conducted on the extension section blank formed by splicing and welding the scalloped segments, so that the scalloped segments of the extension section blank are rolled into conical edge rolling from a fan shape; performing assembly positioning and tailored blank laser welding on the last welding seam of the extension section blank; all laser welding seams of the extending section blank are rolled; according to the method, the tailor-welded extension section is bulged, so that the extension section blank is bulged to the extension section, the problem that a product is scrapped due to continuous cracking of a welding seam after the large-size thin-wall high-temperature alloy extension section is formed and tailor-welded and bulged can be solved, and the reliability of the product is improved.

Description

Technical Field

[0001] The present invention relates to an assembly and welding method for a large-sized single-wall nozzle extension made of superalloy, belonging to the field of laser welding and bulging process control for butt-welded structures. Background Art

[0002] The nozzle extension is an important component of a liquid rocket engine. In the past, a single-wall superalloy extension blank (wall thickness ≤ 1.0 mm, minimum diameter ≥ 1000 mm, length ≥ 1500 mm) was composed of multiple segments. After the fan-shaped segments were butt-welded by tungsten inert gas welding / microbeam plasma welding, the longitudinal weld quality of the fan-shaped segments was inspected by X-ray flaw detection and met the QJ1842A-2011 Class I standard. Then, a bulging process was used to bulge the welded extension blank into an extension.

[0003] However, the following problems will occur when using the above process: ① After the argon arc weld of the extension blank is ground, the base metal and the weld surface at the fusion line will be uneven, that is, continuous undercut defects will appear at the weld toe, increasing the stress concentration at the weld toe; at the same time, the measured remaining wall thickness of the weld will be thinned, reducing the mechanical properties such as tensile strength of the joint; ② After the product is bulged, some welds will crack. Macroscopic inspection shows that the fracture parts mostly crack along the weld fusion line and are locally broken inside the weld, resulting in product scrapping, causing significant economic losses and delaying the production progress.

[0004] Therefore, for a large-sized single-wall nozzle extension made of superalloy, a suitable assembly and welding process is needed to achieve no remaining wall thickness reduction and undercut defects after the extension blank is butt-welded, and at the same time ensure that the welds of the bulged extension blank have no cracks and pores. Summary of the Invention

[0005] The technical problem solved by the present invention is: aiming at the problems of wall thickness reduction, weld toe undercut, and weld cracking after bulging that occur after the weld is ground in the current existing technology, an assembly and welding method for a large-sized single-wall nozzle extension made of superalloy is proposed.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] An assembly and welding method for a large-sized single-wall nozzle extension made of superalloy, comprising:

[0008] Selecting an extension blank of a fan-shaped segment, and cleaning and pre-assembling the extension blank;

[0009] Performing assembly positioning and laser welding on the butt-joint positions of the segments of adjacent extension blanks;

[0010] Performing curling treatment on the segments that have completed laser welding;

[0011] Perform assembly positioning and laser welding on the butt joint of the last extended section blank exposed after curling processing;

[0012] Conduct non-destructive flaw detection inspections on all laser weld seams of the extended section blank;

[0013] Use rolling equipment to successively roll all laser weld seams of the extended section blank that have passed non-destructive flaw detection inspections;

[0014] Perform bulging on the extended section blank after rolling processing to obtain a complete extended section structure.

[0015] The number of segments of the extended section blank is N, and the number of butt welds between the segments is N - 1. The method for cleaning the extended section blank is as follows:

[0016] Dip a white silk cloth in alcohol or gasoline to clean the edges of the segments to ensure no oil stains and impurities before welding;

[0017] The method for pre-welding trial assembly is as follows:

[0018] Conduct trial assembly on the butting surfaces of two adjacent segments to ensure that the butt joint clearance and misalignment between the edges of any two adjacent segments are not greater than the preset values;

[0019] Weld arc starting pieces of the same thickness and the same material at both ends of the butt joint of the segments to be welded as preparation before welding.

[0020] The method for performing laser welding on the 1st to (N - 1)th butt joints of the extended section blank until the (N - 1) butt welds between N segments are completed, which is regarded as the method for assembly positioning and laser welding of the butt joint positions of the segments of adjacent extended section blanks, is as follows:

[0021] Use a vertical assembly welding tooling to perform laser positioning welding on the butt joint positions of two adjacent segments;

[0022] Perform laser formal welding on the butt joint positions of two adjacent segments after laser positioning welding;

[0023] Perform laser finishing welding on the butt joint positions of two adjacent segments after laser formal welding.

[0024] The method for laser positioning welding is as follows:

[0025] Open the vertical assembly welding tooling and fix any two adjacent segments to be processed in the vertical direction to ensure that the butt joint misalignment and butt joint clearance are within the preset ranges;

[0026] Use tungsten inert gas welding method to perform non-wire feeding positioning welding on the butt joint of two adjacent segments to form an assembled whole, and perform positioning welding until the surface of the positioning points at the butt joint positions of the two segments shines and there are no black marks;

[0027] The method of laser formal welding is as follows:

[0028] Open the horizontal assembly welding tooling, jointly fix the butt joints of two adjacent segment pieces after laser positioning welding with the vertical assembly welding tooling, introduce argon gas for welding, use a laser to scan the laser weld path of the butt joints of the segment pieces, and perform laser formal welding on the butt joints according to the scanned path;

[0029] The method of laser dressing welding is as follows:

[0030] After completing the laser formal welding, perform dressing welding along the center of the weld seam at a preset welding angle until the surface of the weld seam shines after welding.

[0031] When the welding of the first butt joint among the first to (N - 1) butt joints of the laser welding extension section blank is completed, sequentially traverse the next butt joint and perform laser welding until the (N - 1) butt welds among N segment pieces are welded and then enter the curling process.

[0032] During the processes of laser positioning welding, laser formal welding, and laser dressing welding, the welding angles of the laser gun heads are the same and back gas protection is carried out.

[0033] The method of curling the segment pieces is as follows:

[0034] Pre-bend the straight edge parts on both sides of the butt joint after completing laser welding, curl the butt joint from a fan shape into a conical shape, make the back side of the laser weld curl inside the conical barrel, and ensure a smooth transition of the inner surface of the conical barrel;

[0035] Correct the exposed butt joint to ensure that the last butt joint, i.e., the Nth butt joint, of the exposed extension section blank is ready for assembly welding.

[0036] Before preparing for the assembly welding of the Nth butt joint, insert the conical barrel of the extension section blank after curling into the horizontal assembly welding tooling, press it tightly and introduce argon gas to achieve positioning.

[0037] The method of rolling treatment for the laser weld seam is as follows:

[0038] According to the preset rolling pressure, use rolling equipment to sequentially roll the N laser weld seams of the segment pieces of the extension section blank, control the rolling wheel to align with the center position of the laser weld seam, roll from the arc starting piece position at one end of the laser weld seam to the arc starting piece position at the other end, and after rolling, use a wire brush to polish the inner and outer surfaces of the N weld seams of the extension section blank to make the weld seam surface shiny and smooth.

[0039] The method of bulging treatment is as follows:

[0040] Apply lubricating oil on the inner surface of the large end of the conical cylinder along the generatrix within a certain range, and use a precision press and special male and female molds to expand the conical cylinder; after expansion, perform high-temperature solution heat treatment, and the number of expansion and heat treatment times is 2 - 3 times.

[0041] The advantages of the present invention compared with the prior art are as follows:

[0042] (1) The assembly and welding method of a large-size high-temperature alloy single-wall nozzle extension section provided by the present invention performs segmented laser welding on the large-size thin-wall GH3044 high-temperature alloy extension section, solves the problem of continuous cracking of the weld after forming and welding expansion of the large-size thin-wall high-temperature alloy extension section, improves the reliability of the product, and reduces the economic cost caused by product scrapping; at the same time, uses a rolling process instead of the original grinding process for the weld after laser welding, solves the problems of wall thickness reduction and weld undercut of the remaining weld after welding, improves the consistency of the weld surface state, making the weld protrude or cut into the matrix by no more than 0.1 mm; at the same time, reduces the labor intensity caused by grinding the weld, improves production efficiency, and avoids problems such as metal dust pollution caused by grinding the weld.

[0043] (2) The assembly positioning welding tooling designed in the present invention is provided with a back gas protection groove, which can meet the back gas protection of thin-wall welded parts with different lengths during argon arc positioning and laser welding, and avoids defects such as undercut, cracks and pores in the weld due to poor back gas protection effect during positioning and laser welding. Description of the Drawings

[0044] Figure 1 It is a schematic diagram of the weld of the three segments of the extension section blank in the present invention;

[0045] Figure 2 It is a schematic diagram of the laser welding tooling for large-size thin-wall parts in the present invention;

[0046] Figure 3 It is a schematic diagram of the structure of the pressure plate assembly of the laser welding tooling in the present invention;

[0047] Figure 4 It is a schematic diagram of the structure of the matrix assembly of the laser welding tooling in the present invention;

[0048] Figure 5 It is a schematic diagram of the structure of the ejector rod assembly of the laser welding tooling in the present invention. Detailed Embodiments

[0049] An assembly and welding method for a large-sized single-wall nozzle extension of superalloy, using a positioning welding process device, sequentially performing gas shielded positioning welding and laser seam welding on the butt welds of all segments; rolling the extension blank formed by segment welding into a conical shape from a fan shape; performing assembly positioning and laser seam welding on the last weld of the extension blank; rolling all the laser welds of the extension blank; bulging the welded extension to form the extension blank into an extension, which can solve the problem of continuous cracking of the welds after forming and bulging of the large-sized thin-walled superalloy extension, resulting in product rejection, and improve the reliability of the product.

[0050] The assembly and welding method for a large-sized single-wall nozzle extension of superalloy is as follows:

[0051] Select an extension blank of segment in fan shape, and clean the extension blank and perform pre-welding trial assembly;

[0052] Perform assembly positioning and laser welding on the butt joint positions of adjacent segments of the extension blank;

[0053] Perform rolling treatment on the segments that have completed laser welding;

[0054] Perform assembly positioning and laser welding on the last butt joint of the extension blank exposed after rolling treatment;

[0055] Perform non-destructive flaw detection inspection on all laser welds of the extension blank;

[0056] Use a rolling device to sequentially perform rolling treatment on all laser welds of the extension blank that have passed non-destructive flaw detection inspection;

[0057] Perform bulging on the extension blank after rolling treatment to obtain a complete extension structure.

[0058] The number of segments of the extension blank is N, and the number of butt welds between segments is N - 1. The method for cleaning the extension blank is as follows:

[0059] Use a white silk cloth dipped in alcohol or gasoline to clean the edges of the segments to ensure no oil stains and impurities before welding;

[0060] The method for pre-welding trial assembly is as follows:

[0061] Perform trial assembly on the butting surfaces of two adjacent segments to ensure that the butting gap and misalignment amount between the edges of any two adjacent segments are not greater than the preset value;

[0062] Weld arc starting pieces of the same thickness and the same material at both ends of the butting joint of the segments to be welded as preparation before welding.

[0063] The method for assembling and positioning the butt joint positions of adjacent extended section blanks and performing laser welding is as follows: After laser welding the 1st to (N - 1) butt joints of the extended section blanks until the (N - 1) butt welds between N segments are completed,

[0064] Use a vertical assembly and welding tooling to perform laser positioning welding on the butt joint positions of two adjacent segments;

[0065] Perform laser formal welding on the butt joint positions of two adjacent segments after laser positioning welding;

[0066] Perform laser finishing welding on the butt joint positions of two adjacent segments after laser formal welding.

[0067] The method for laser positioning welding is as follows:

[0068] Open the vertical assembly and welding tooling and fix any two adjacent segments to be processed vertically to ensure that the butt joint misalignment and butt joint gap are within the preset ranges;

[0069] Use the tungsten inert gas welding method to perform non - wire positioning welding on the butt joints of two adjacent segments to form an assembled unit. The positioning welding is carried out until the surface of the positioning points at the butt joint positions of the two segments is shiny and has no black marks;

[0070] The method for laser formal welding is as follows:

[0071] Open the horizontal assembly and welding tooling, jointly fix the butt joints of two adjacent segments after laser positioning welding with the vertical assembly and welding tooling, introduce argon gas for welding, use a laser to scan the laser weld path of the butt joints of the segments, and perform laser formal welding on the butt joints according to the scanned path;

[0072] The method for laser finishing welding is as follows:

[0073] After completing laser formal welding, perform finishing welding along the center of the weld seam at a preset welding angle until the surface of the weld seam is shiny after welding.

[0074] When the first butt joint among the 1st to (N - 1) butt joints of the extended section blanks is welded, sequentially traverse the next butt joint and perform laser welding until the (N - 1) butt welds between N segments are completed and then enter the curling process.

[0075] During the processes of laser positioning welding, laser formal welding, and laser finishing welding, the welding angles of the laser gun heads are the same and back - gas protection is carried out.

[0076] The method for curling the segments is as follows:

[0077] Pre-bend the straight-edge parts on both sides of the butt joint where laser welding is completed, roll the butt joint from a fan shape into a conical shape, make the rolled circle on the back side of the laser weld inside the conical barrel, and ensure a smooth transition of the inner surface of the conical barrel;

[0078] Correct the exposed butt joint to ensure that the last, i.e., the Nth, butt joint of the exposed extension blank is ready for assembly welding.

[0079] Before preparing for the assembly welding of the Nth butt joint, insert the conical barrel of the extension blank after hemming treatment into the horizontal assembly welding fixture, press it tightly, and introduce argon gas to achieve positioning.

[0080] The method for rolling the laser weld is as follows:

[0081] Use the rolling equipment to roll the N laser welds of the extension blank segments in sequence according to the preset rolling pressure, control the rolling wheel to align with the exact center position of the laser weld, roll from the position of the arc starting piece at one end of the laser weld to the position of the arc starting piece at the other end, and after rolling, use a wire brush to polish the inner and outer surfaces of the N welds of the extension blank to make the weld surface shiny and smooth.

[0082] The method for bulging is as follows:

[0083] Apply lubricating oil on the inner surface of the large end of the conical barrel within a certain range along the generatrix, use a precision press and special male and female molds to bulge the conical barrel; after bulging, perform high-temperature solution heat treatment, and the number of bulging and heat treatment times is 2 - 3 times.

[0084] The following is a further description in combination with the drawings in the specification and preferred embodiments:

[0085] In the current embodiment, as Figure 1 shown, it is a schematic diagram of the welds of the three segments of the extension blank; as Figure 2 shown, it is a schematic diagram of the laser welding fixture; as Figure 3 shown, it is a schematic diagram of the structure of the pressing plate assembly of the laser welding fixture; as Figure 4 shown, it is a schematic diagram of the structure of the tire body assembly of the laser welding fixture; as Figure 5 shown, it is a schematic diagram of the structure of the ejector rod assembly of the laser welding fixture, and the specific reference numerals are:

[0086] 1. Petal I; 2. Weld seam A; 3. Petal II; 4. Weld seam B; 5. Petal III; 6. Vertical assembly welding tooling; 61. Clamping pliers; 62. Long bolt; 63. Press plate assembly; 631. Compression bolt; 632. Bridge; 633. Pressure block; 64. Matrix assembly; 641. Copper gasket; 642. Matrix; 643. Threaded straight-through quick connector; 644. Argon gas pipe; 645. Groove; 646. Vent hole; 65. Bolt; 66. Hinge shaft; 7. Horizontal assembly welding tooling; 71. Clamping pliers; 72. Press plate assembly; 73. Matrix assembly; 74. Bolt; 8. Ejector rod assembly; 81. Lifting rod; 82. Rotating nut; 83. Sleeve; 84. Hinge shaft hole.

[0087] Assembly and welding method for large-size superalloy single-wall nozzle extension section, the specific steps include:

[0088] Step 1: The petals are fan-shaped. By performing S1 - S5, assemble, position, and weld the butt joint positions of any two adjacent petals of the extension section blank:

[0089] S1. Perform pre-welding trial assembly and cleaning on the butt joint positions of two adjacent petals.

[0090] S2. Assemble, position, and tack-weld the butt joint positions of two adjacent petals, and weld arc starting tabs at both ends of the butt joint positions of the petals.

[0091] S3. Perform laser positioning welding on the butt joint positions of two adjacent petals.

[0092] S4. Perform laser formal welding on the butt joint positions of two adjacent petals.

[0093] S5. Perform laser finishing welding on the butt joint positions of two adjacent petals.

[0094] If the number of petals of the extension section blank is N and the number of butt welds between the petals is N - 1, by repeatedly performing S1 - S5, laser-weld the 1st to (N - 1)th butt joints of the extension section blank until the (N - 1) butt welds between N petals are welded.

[0095] Step 2: Roll the petals after laser bead welding to form the extension section blank from a fan shape to a conical shape, facilitating the assembly and welding of the last (i.e., the Nth) butt joint of the extension section blank.

[0096] Step 3: Repeatedly perform S1 - S5 in Step 1 to assemble, position, and laser-weld the last (i.e., the Nth) butt joint of the extension section blank.

[0097] Step 4: Perform non-destructive flaw detection on all laser welds of the extension section blank to ensure the surface quality of the welds.

[0098] Step Five: Use a rolling device to roll all the laser welds of the blank of the extension section in sequence to release the welding residual stress of the laser welds of the thin-walled part.

[0099] Step Six: Perform bulging on the blank of the extension section to bulge it into the extension section.

[0100] Before welding in Step One, pre-assemble and clean the butting surfaces of two adjacent segments, and at the same time weld arc starting pieces of the same thickness and the same material at both ends of the welding joint. The welding wire grade used is HGH367, the welding wire diameter is Φ1.2mm, the argon gas flow rate is 8 - 12L / min, and the welding current is 50 ± 10A.

[0101] In Step One, use the vertical assembly welding tooling 6 to assemble and perform tungsten inert gas positioning welding on the segment joints of the blank of the extension section. During assembly, ensure that the butting misalignment and butting gap between any two adjacent segments ≤ 0.1mm; during positioning welding, perform back gas protection, the argon gas flow rate is 8 - 15L / min, the positioning welding current is 60 ± 10A, the distance between positioning welds is 40 - 50mm, and the size of the positioning welds is 3 - 5mm.

[0102] In Step One, use the vertical assembly welding tooling 6 or the horizontal assembly welding tooling 7 to perform laser welding on the segment joints of the blank of the extension section, including laser positioning welding, laser assembly welding, and laser formal welding. During the welding process, tilt the gun head of the laser along the welding direction of the weld by 4 - 10°, the welding power is 1400 - 1800W, the welding speed is 0.04 - 0.05m / s, the frequency is 60Hz, and the defocus amount is 1mm.

[0103] In Step Two, after laser welding of the 1st to (N - 1)th joints of N segments of the blank of the extension section, perform curling to roll the large sector-shaped material into a conical cylinder, and finally correct the joints after curling to make the joint gap ≤ 0.1mm and the joint offset ≤ 0.1mm.

[0104] In Step Three, use the horizontal assembly welding tooling 7 to perform laser positioning welding, laser formal welding, and laser finishing welding on the Nth weld of the blank of the extension section, and introduce argon gas at a flow rate of 8 - 12L / min during the welding process.

[0105] In Step Four, ensure that all welds have no defects such as cracks and pores, and meet the Class I standard of "QJ20693 - 2018 Laser Welding Technology for Superalloys".

[0106] In the fifth step, a rolling device is used to roll the N laser welds of the extended section blank petal in sequence. The rolling pressure is 800 - 1000 N. When rolling, align the rolling wheel with the exact center position of the laser weld, roll from the arc starting piece position at one end of the laser weld to the arc starting piece position at the other end, and keep the rolling speed moderate. After rolling, use a wire brush to slightly polish the inner and outer surfaces of the N welds of the extended section blank to make the weld surface shiny and smooth.

[0107] In the sixth step, apply oil lubrication within a range of 200 mm along the generatrix on the inner surface of the large end of the conical cylinder. Use a precision press and special male and female molds to expand the conical cylinder. After expansion, perform high-temperature solution heat treatment. The number of expansion and heat treatment times is 2 - 3 times to make it into the extended section.

[0108] Example 1

[0109] The extended section blank of single-wall superalloy GH3044 is formed by welding 5 petals:

[0110] (1) Before welding the extended section blank of single-wall superalloy GH3044, conduct trial assembly and cleaning on the butting surfaces of two adjacent petals to ensure that the butting gap between the edges of any two adjacent petals is not greater than 0.1 mm, and the dislocation amount is not greater than 0.1 mm. Use a white silk cloth dipped in alcohol or gasoline to clean the edges of the petals to ensure no oil stains and impurities before welding. Weld GH3044 arc starting pieces with a thickness of 0.7 mm at both ends of the butting seams of the 5 petals to be welded. The welding wire grade used is HGH367, the wire diameter is Φ1.2 mm, the argon gas flow rate is 8 - 12 L / min, and the welding current is 40 A.

[0111] (2) Use the vertical assembly welding tooling 6 to assemble and perform tungsten inert gas positioning welding on the 4 petal seams of the extended section blank. First, open the clamping pliers 61, and use the long bolt 62 and the hinge shaft 66 to horizontally place the pressing plate assembly 63. Then, place 2 / 3 of the seams of any two adjacent petals on the groove 645 of the carcass assembly 64, and finally install the pressing plate assembly 63. There are multiple threaded holes on the bridge 632 of the pressing plate assembly 63. By adjusting the handles and pressing blocks 633 of multiple pressing bolts 631, ensure that the butting dislocation amount and the butting gap amount between any two adjacent petals are ≤ 0.1 mm.

[0112] (3) Pass 10 L / min of argon gas into the vertical assembly welding tooling 6 for tungsten inert gas positioning welding. The welding current is 40 A, the spacing between the positioning welding points is 40 mm, and the size of the positioning welding points is 3 mm, ensuring that the surface of the positioning points after assembly and positioning is shiny and has no black marks.

[0113] (4) Laser welding is performed on the butt joints of the segment petals on the vertical assembly and welding tooling 6. First, argon gas at a flow rate of 10 L / min is introduced into the groove 645 of the assembly and welding tooling 6. Then, a laser is used to scan the laser welding path of the butt joints of the segment petals to prevent the laser from deviating from the center of the butt joints of the segment petals during the laser welding process.

[0114] (5) During the positioning welding process, the gun head of the laser is tilted 5° along the welding direction of the weld seam, with a welding power of 1500 W, a welding speed of 0.05 m / s, a frequency of 60 Hz, and a defocus amount of 1 mm; during the formal welding process, the gun head of the laser is tilted 5° along the welding direction of the weld seam, with a welding power of 1700 W, a welding speed of 0.05 m / s, a frequency of 60 Hz, and a defocus amount of 1 mm; during the dressing welding process, the gun head of the laser is tilted 5° along the welding direction of the weld seam, with a welding power of 1400 W, a welding speed of 0.05 m / s, a frequency of 60 Hz, and a defocus amount of 1 mm.

[0115] (6) After laser welding the 1st to 4th butt joints of the 5 segment petals of the blank of the extension section, curling is performed to form a large fan-shaped blank. First, the two straight-edge parts of the fan-shaped blank are pre-bent, and then the large fan-shaped blank is curled into a conical cylinder, with the back side of the laser weld seam curled inside the conical cylinder to ensure a smooth transition of the inner surface of the conical cylinder. Finally, the butt joints after curling are corrected so that the butt joint gap is ≤0.1 mm and the butt joint offset is ≤0.1 mm.

[0116] (7) The horizontal assembly and welding tooling 7 is used to weld the 5th weld seam of the blank of the extension section. The ejector rod assembly 8 is horizontally placed through the hinge shaft hole 84, and the conical cylinder of the blank of the extension section is inserted onto the horizontal assembly and welding tooling 7. The 5th butt joint of the blank of the extension section is placed on the groove of the matrix assembly 73 through the pressing plate assembly 72, the matrix assembly 73, and the clamping pliers 71, and argon gas is introduced. Then, laser positioning welding, laser formal welding, and laser dressing welding are performed on the 5th butt joint.

[0117] (8) A rolling device is used to roll the 5 laser weld seams of the segment petals of the blank of the extension section in sequence, with a rolling pressure of 800 N. During rolling, the rolling wheel is aligned with the center position of the laser weld seam, and it is rolled from the arc starting piece position at one end of the laser weld seam to the arc starting piece position at the other end, with a moderate rolling speed; after rolling, a wire brush is used to slightly polish the inner and outer surfaces of the 5 weld seams of the blank of the extension section to make the weld seam surface shiny and smooth.

[0118] (9) Lubricating oil is applied to the inner surface of the large end of the conical cylinder of the extension section within a range of 200 mm along the generatrix. A precision press and special male and female molds are used to expand the conical cylinder; after expansion, high-temperature solution heat treatment is performed, and the number of expansion and heat treatment is 2 times to form the extension section.

[0119] Example 2

[0120] The single-wall superalloy GH3230 extension section blank is welded by 8 segments:

[0121] (1) Before welding the single-wall superalloy GH3230 extension section blank, fit and clean the butt joints of two adjacent segments to ensure that the butt joint gap between the edges of any two adjacent segments is no more than 0.1 mm and the misalignment is no more than 0.1 mm; use white silk cloth dipped in alcohol or gasoline to clean the edges of the segments to ensure no oil stains and impurities before welding; weld GH3230 arc starting pieces with a thickness of 1.1 mm at both ends of the 8 segments to be welded. The welding wire grade used is HGH367, the wire diameter is Φ1.2 mm, the argon gas flow rate is 12 L / min, and the welding current is 60 A.

[0122] (2) Use the vertical assembly welding fixture 6 to assemble and perform tungsten inert gas (TIG) positioning welding on the 7 segment butt joints of the extension section blank. First, open the clamping pliers 61, and use the long bolt 62 and hinge shaft 66 to place the pressing plate assembly 63 horizontally; then place 2 / 3 of the butt joint of any two adjacent segments on the groove 645 of the carcass assembly 64, and finally install the pressing plate assembly 63. There are multiple threaded holes on the bridge 632 of the pressing plate assembly 63. By adjusting the handles and pressure blocks 633 of multiple pressing bolts 631, ensure that the butt joint misalignment and butt joint gap between any two adjacent segments are ≤0.1 mm.

[0123] (3) Pass 10 L / min of argon gas into the vertical assembly welding fixture 6 for TIG positioning welding. The welding current is 60 A, the distance between the positioning welds is 50 mm, and the size of the positioning welds is 5 mm. Ensure that the surface of the positioning points after assembly and positioning is shiny and has no black marks.

[0124] (4) Perform laser welding on the segment butt joints on the horizontal assembly welding fixture 7. First, pass 12 L / min of argon gas into the groove of the assembly welding fixture 7; then use the laser to scan the laser welding path of the segment butt joints to prevent the path from deviating from the center of the segment butt joint during laser welding.

[0125] (5) During positioning welding, tilt the gun head of the laser by 7° along the welding direction of the weld. The welding power is 1600 W, the welding speed is 0.04 m / s, the frequency is 60 Hz, and the defocus amount is 1 mm; during formal welding, tilt the gun head of the laser by 7° along the welding direction of the weld. The welding power is 1800 W, the welding speed is 0.05 m / s, the frequency is 60 Hz, and the defocus amount is 1 mm; during dressing welding, tilt the gun head of the laser by 7° along the welding direction of the weld. The welding power is 1500 W, the welding speed is 0.05 m / s, the frequency is 60 Hz, and the defocus amount is 1 mm.

[0126] (6) After laser welding the 1st to 7th seams of the 8 segments of the blank of the extension section, roll it into a large sector-shaped blank. First, pre-bend the two straight-edge parts of the sector-shaped blank, and then roll the large sector-shaped blank into a conical cylinder, with the back side of the laser weld seam rolled inside the conical cylinder to ensure a smooth transition of the inner surface of the conical cylinder. Finally, correct the seam after rolling to make the seam gap ≤ 0.1 mm and the seam offset ≤ 0.1 mm.

[0127] (7) Use the horizontal assembly welding tooling 7 to weld the 8th weld seam of the blank of the extension section. Horizontally place the ejector rod assembly 8 through the hinge shaft hole 84, insert the conical cylinder of the blank of the extension section onto the horizontal assembly welding tooling 7, place the 8th seam of the blank of the extension section on the groove of the carcass assembly 73 through the pressing plate assembly 72, the carcass assembly 73 and the clamping pliers 71, introduce argon gas, and then perform laser positioning welding, laser formal welding and laser finishing welding on the 8th seam.

[0128] (8) Use the rolling equipment to roll the 8 laser weld seams of the segments of the blank of the extension section in sequence, with a rolling pressure of 1000 N. During rolling, align the rolling wheel with the exact center position of the laser weld seam, roll from the arc starting piece position at one end of the laser weld seam to the arc starting piece position at the other end, and the rolling speed should be appropriate; after rolling, use a wire brush to slightly polish the inner and outer surfaces of the 8 weld seams of the blank of the extension section to make the weld seam surface shiny and smooth.

[0129] (9) Apply engine oil lubrication within a range of 240 mm along the generatrix on the inner surface of the large end of the conical cylinder of the extension section, and use a precision press and special male and female molds to expand the conical cylinder; after expansion, perform high-temperature solution heat treatment, and the number of expansion and heat treatment is 3 times to make it into the extension section.

[0130] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention all fall within the protection scope of the technical solution of the present invention.

[0131] The content not detailedly described in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. An assembly and welding method for a large-size superalloy single-wall nozzle extension section, characterized in that Including: Select a blank workpiece of the extended section of the fan-shaped melon petal, and clean the blank workpiece of the extended section and conduct pre-welding trial assembly; Perform assembly positioning and laser welding on the butting positions of the melon petals of adjacent blank workpieces of the extended section; Perform curling treatment on the melon petals after laser welding is completed; Perform assembly positioning and laser welding on the butting seam of the last blank workpiece of the extended section exposed after curling treatment; Conduct non-destructive flaw detection inspection on all laser weld seams of the blank workpiece of the extended section; Use rolling equipment to sequentially roll all laser weld seams of the blank workpiece of the extended section that have passed non-destructive flaw detection inspection; Perform bulging on the blank workpiece of the extended section after rolling treatment to obtain a complete extended section structure.

2. The assembly and welding method of a large-size superalloy single-wall nozzle extension section according to claim 1, characterized in that: The method for cleaning the blank workpiece of the extended section is: Dip a white silk cloth in alcohol or gasoline to clean the edges of the melon petals to ensure no oil stains and impurities before welding; The method for pre-welding trial assembly is: Conduct trial assembly on the butting surfaces of two adjacent melon petals to ensure that the butting gap and misalignment amount between the edges of any two adjacent melon petals are not greater than the preset value; Weld arc starting pieces of the same thickness and the same material at both ends of the butting seam of the melon petals to be welded as preparation before welding.

3. The assembly and welding method of a large-size superalloy single-wall nozzle extension section according to claim 1, characterized in that: The number of melon petals of the blank workpiece of the extended section is N, the number of butting weld seams between the melon petals is N - 1, and the method for performing laser welding on the 1st to (N - 1)th butting seams of the blank workpiece of the extended section until the (N - 1) butting weld seams between N melon petals are welded is regarded as the method for performing assembly positioning and laser welding on the butting positions of the melon petals of adjacent blank workpieces of the extended section: Use a vertical assembly welding tooling to perform laser positioning welding on the butting positions of two adjacent melon petals; Perform laser formal welding on the butting positions of two adjacent melon petals after laser positioning welding; Perform laser finishing welding on the butting positions of two adjacent melon petals after laser formal welding.

4. The assembly and welding method of a large-size superalloy single-wall nozzle extension section according to claim 3, characterized in that: The method for laser positioning welding is: Open the vertical assembly welding tooling and fix any two adjacent melon petals to be processed in the vertical direction to ensure that the misalignment amount and butting gap amount are within the preset range; Use tungsten inert gas welding method to perform non-wire feeding positioning welding on the butting seam of two adjacent melon petals to form an assembled whole, and perform positioning welding until the surface of the positioning point at the butting seam position of the two melon petals shines and has no black marks; The method for laser formal welding is: Open the horizontal assembly welding tooling, jointly fix the butting seam of two adjacent melon petals after laser positioning welding with the vertical assembly welding tooling, introduce argon gas for welding, use a laser to scan the laser weld seam path of the butting seam, and perform laser formal welding on the butting seam according to the scanned path; The method for laser finishing welding is: After laser formal welding is completed, perform finishing welding along the center of the weld seam at a preset welding angle until the surface of the weld seam shines after welding.

5. The assembly and welding method of a large-size superalloy single-wall nozzle extension section according to claim 4, characterized in that: After the welding of the first butt joint among the first to the (N-1)th butt joints of the extension section blank by laser welding is completed, sequentially traverse the next butt joint and perform laser welding until the (N-1) butt welds among the N segments are welded and then enter the curling process.

6. The assembly and welding method of a large-size superalloy single-wall nozzle extension section according to claim 4, characterized in that: During the processes of laser positioning welding, laser formal welding, and laser finishing welding, the welding angles of the laser gun heads are the same and back gas protection is carried out.

7. The assembly and welding method of a large-size superalloy single-wall nozzle extension section according to claim 4, characterized in that: The method of curling the segments is as follows: Pre-bend the straight edge parts on both sides of the butt joint after laser welding is completed, curl the butt joint from a fan shape into a conical shape, make the curled part on the back side of the laser weld inside the conical barrel, and ensure a smooth transition of the inner surface of the conical barrel; Correct the exposed butt joint to ensure that the last, i.e., the Nth, butt joint of the extension section blank is ready for assembly welding.

8. The assembly and welding method of a large-size superalloy single-wall nozzle extension section according to claim 5, characterized in that: Before preparing for the assembly welding of the Nth butt joint, insert the conical barrel of the extension section blank after flanging into a horizontal assembly welding fixture, press it tightly and introduce argon gas to achieve positioning.

9. The assembly and welding method of a large-size superalloy single-wall nozzle extension section according to claim 5, characterized in that: The method of rolling the laser weld is as follows: Use a rolling device to roll the N laser welds of the extension section blank segments in sequence according to a preset rolling pressure, control the rolling wheel to align with the exact center position of the laser weld, roll from the starting tab position at one end of the laser weld to the ending tab position at the other end, and after rolling, use a wire brush to polish the inner and outer surfaces of the N welds of the extension section blank to make the weld surface shiny and smooth.

10. The assembly and welding method of a large-size superalloy single-wall nozzle extension section according to claim 9, characterized in that: The method of bulging is as follows: Apply machine oil lubrication on the inner surface of the large end of the conical barrel within a certain range along the generatrix, use a precision press and special male and female molds to bulge the conical barrel; after bulging, perform high-temperature solution heat treatment, and the number of bulging and heat treatment times is 2 to 3 times.

Images