A welding processing method for thin-walled arc parts

Abstract

The invention discloses a welding processing method for thin-walled arc-shaped parts, and relates to the technical field of thin-walled arc-shaped parts processing; in order to solve the problem of low dimensional accuracy of thin-walled arc-shaped parts processing; specifically includes the following operation steps: preparing profiles: processing matching annular parts tooling according to the outer diameter of the required product; performing solid solution aging on the annular parts tooling; performing preliminary rough processing on the annular parts tooling: performing rough turning processing on the outer / inner diameter of the annular parts tooling according to the outer / inner diameter through-hole parameters of the required product; performing stable heat treatment; performing secondary fine processing on the annular parts tooling: performing fine turning processing on the outer / inner diameter of the annular parts tooling according to the outer / inner diameter through-hole parameters of the required product; wire cutting the annular parts tooling to obtain an arc-shaped workpiece: cutting the annular parts tooling into two or more annular parts that match the product design size width. The invention first processes the workpiece body and then welds, which effectively improves the precision of the arc-shaped parts processing size.

Description

Technical Field

[0001] The invention relates to the technical field of processing thin-walled arc-shaped parts, and in particular to a welding processing method for thin-walled arc-shaped parts. Background Art

[0002] Thin-walled arc-shaped parts are widely used in the aerospace industry, such as sealing rings, turbine outer rings, etc. Due to the high precision requirements, they are usually processed by CNC milling and welding. The processing is restricted by the welding method and welding process, and the impurity content and grain size of the parent material must be controlled. Some welding also requires proper preheating of the weldment and welding under low constraint conditions. However, no matter what method is used for repair welding, residual shrinkage tensile stress will be generated at the weld after welding. If this stress is not removed, it will accelerate damage at the stress concentration during use. For example, when the thin-walled ring is cut, the arc-shaped part will have dimensional deformation problems. Therefore, in order to reduce the residual tensile stress of the workpiece, it is necessary to optimize the processing technology and parameters.

[0003] During the processing of thin-walled arc parts, heat treatment is performed to reduce residual stress deformation and thus improve the accuracy of arc part processing dimensions, thereby achieving the effect of improving the processing efficiency of thin-walled arc parts and reducing their deformation. Therefore, we propose a welding processing method for thin-walled arc parts. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a welding method for thin-walled arc-shaped parts.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A welding method for thin-walled arc-shaped parts includes the following steps:

[0007] S1: Prepare profiles: Process matching ring parts tooling according to the outer diameter of the required product;

[0008] S2: Solution aging of the ring tooling;

[0009] S3: Perform preliminary rough machining on the ring-shaped tooling: Rough machining is performed on the outer / inner diameter of the ring-shaped tooling according to the outer / inner diameter through-hole parameters of the required product;

[0010] S4: stabilization heat treatment;

[0011] S5: Perform secondary finishing on the ring-shaped tooling: Perform finishing turning on the outer / inner diameter of the ring-shaped tooling according to the outer / inner diameter through-hole parameters of the required product;

[0012] S6: Wire cutting the annular tooling to obtain an arc-shaped workpiece: cutting the annular tooling into two or more annular parts that match the width of the product design size, and then cutting the annular parts into the required arc-shaped workpiece;

[0013] S7: clean the surfaces of the arc workpiece and the butt joint, position and fix the arc workpiece and the butt joint in close contact on a fixture, and add an isolation pad on one side of the butt joint between the arc workpiece and the butt joint, i.e., the weld;

[0014] S8: Welding construction: Use symmetrical welding to perform simultaneous positioning welding at both ends of the butt joint, and then perform fixed welding in the middle of the butt joint to obtain a processed part;

[0015] S9: Quality inspection: Check whether the weld of the processed part is full and leaky, and check whether the weld is leaking.

[0016] Preferably: the solution aging treatment method includes the following contents:

[0017] Aa: Place the ring-shaped tooling into a heating furnace, heat to 400-500°C, keep warm for 1-4 hours, and cool down after removing from the furnace;

[0018] Ab: Put the cooled annular tooling into the heating furnace again, heat to 100-135°C, keep warm for 5-20 hours, and cool down after taking out of the furnace;

[0019] The cooling methods include air cooling, water cooling and furnace cooling.

[0020] Preferably, the operation content of the stabilization heat treatment is: placing the ring-shaped component in a heating furnace, introducing stabilizing elements (Ti and Nb), heating to 880-1100° C., and keeping the temperature for 2-4 hours.

[0021] Preferably: the wire cutting ring tooling includes the following processing requirements:

[0022] Ba: Calculate cutting time and reduce residual stress and deformation;

[0023] Bb: Control the axial feed speed to reduce the efficiency of arc workpiece processing;

[0024] The calculation formula of the cutting processing time is: y2=L / v w .

[0025] Preferably, the method of cleaning the arc-shaped workpiece and the butt joint is one of chemical cleaning and mechanical cleaning.

[0026] Preferably: the beam current of the positioning welding is 8-10 mA, the welding time is 5s-6s, and the maintenance time is 2-4s;

[0027] The gap of the weld is 0 to 0.15 mm.

[0028] Preferably, the quality inspection method includes the following contents:

[0029] Ca: Use a helium leak detector to draw a vacuum to less than 2.0×10-11mbar.L / S, and use alcohol to seal the contact surface;

[0030] Cb: Use helium to purge the weld to detect leaks.

[0031] Preferably: the processing equipment for the preliminary rough machining and the secondary finishing are both CNC lathes;

[0032] The wire cutting processing equipment is a CNC wire cutting machine tool.

[0033] The beneficial effects of the present invention are:

[0034] 1. After improving the comprehensive mechanical properties of the workpiece and thus reducing the residual stress deformation of the workpiece during cutting, the present invention adopts a symmetrical welding method to perform simultaneous positioning welding at both ends of the butt joint, and then performs fixed welding in the middle of the butt joint, using the mutual restraint of weld stress to reduce distortion and deformation. The combination of first processing the workpiece body and then welding effectively improves the accuracy of the arc-shaped part processing size.

[0035] 2. The present invention effectively stabilizes the tooling structure and size through pre-treatment of the annular tooling, thereby obtaining an annular tooling with excellent mechanical properties. In addition, the annular tooling is subjected to stable heat treatment after rough machining and before fine machining, thereby effectively improving the comprehensive mechanical properties and further reducing the residual stress deformation of the parts.

[0036] 3. The present invention controls the cutting processing time and then the cutting speed, thereby controlling the magnitude of the residual stress deformation, and at the same time controls the cutting feed speed, thereby improving the processing efficiency while ensuring the cutting quality of the arc-shaped workpiece.

[0037] 4. The present invention uses a chemical cleaning method to clean the surfaces of the processed arc workpiece and the butt joint. After air drying, the arc workpiece and the butt joint are closely contacted and fixed on a fixture, and a flexibly removable isolation pad is added on one side of the weld to effectively prevent damage to the weld during welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a schematic flow chart of a welding method for thin-walled arc-shaped parts. DETAILED DESCRIPTION

[0039] The technical solution of this patent is further described in detail below in conjunction with specific implementation methods.

[0040] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0041] Embodiment 1:

[0042] A welding method for thin-walled arc parts, such as Figure 1 As shown, the following steps are included:

[0043] S1: Prepare profiles: Process matching ring parts tooling according to the outer diameter of the required product;

[0044] S2: Solution aging of the ring tooling;

[0045] S3: Perform preliminary rough machining on the ring-shaped tooling: Rough machining is performed on the outer / inner diameter of the ring-shaped tooling according to the outer / inner diameter through-hole parameters of the required product;

[0046] S4: stabilization heat treatment;

[0047] S5: Perform secondary finishing on the ring-shaped tooling: Perform finishing turning on the outer / inner diameter of the ring-shaped tooling according to the outer / inner diameter through-hole parameters of the required product;

[0048] S6: Wire cutting the annular tooling to obtain an arc-shaped workpiece: cutting the annular tooling into a plurality of annular parts that match the width of the product design size, and then cutting the annular parts into the required arc-shaped workpieces;

[0049] S7: Clean the surfaces of the arc workpiece and the butt joint, position and fix the arc workpiece and the butt joint in close contact on the fixture, and add an isolation pad on one side of the butt joint between the arc workpiece and the butt joint, i.e., the weld, to prevent damage to the weld during welding;

[0050] S8: Welding construction: Use symmetrical welding to perform simultaneous positioning welding at both ends of the butt joint, and then perform fixed welding in the middle of the butt joint to obtain a processed part, so that the weld stresses are mutually restricted and distortion is reduced;

[0051] S9: Quality inspection: Check whether the weld of the processed part is full and leaky, and check whether the weld is leaking.

[0052] Preferably, the profile includes a blank, a rod, etc.

[0053] The solution aging treatment method comprises the following contents:

[0054] Aa: Place the ring-shaped tooling into a heating furnace, heat to 400-500°C, keep warm for 1-4 hours, and cool down after removing from the furnace;

[0055] Ab: Put the cooled annular tooling into the heating furnace again, heat to 100-135℃, keep warm for 5-20h, and cool down after taking out of the furnace.

[0056] Preferably, the cooling method includes air cooling, water cooling, furnace cooling, etc. The plasticity and toughness of the workpiece are improved, residual stress is preliminarily removed, the structure and size of the tooling are stabilized, and a significant solid solution strengthening effect is obtained under the premise of significantly reducing the energy consumption of heat treatment, so as to obtain a ring-shaped tooling with excellent mechanical properties.

[0057] The processing equipment for the preliminary rough machining and the secondary finishing can be a CNC lathe or other processing equipment.

[0058] The operation content of the stabilization heat treatment is: place the ring-shaped part in a heating furnace, introduce stabilizing elements (Ti and Nb), heat to 880-1100°C, and keep warm for 2-4 hours to improve the comprehensive mechanical properties and further reduce the residual stress deformation of the parts.

[0059] The wire cutting processing equipment may be a CNC wire cutting machine or others.

[0060] The wire cutting ring tooling includes the following processing requirements:

[0061] Ba: Calculate cutting time and reduce residual stress and deformation;

[0062] The calculation formula for cutting processing time is: y2=L / v w , cutting processing time reflects cutting speed, v s ∈(a,b),where y2 is the processing time, in seconds; L is the part width, in mm; v w is the axial feed speed, in mm / s; v s is the cutting speed. When the cutting speed is increased, severe elastic-plastic deformation occurs between the cutter and the workpiece, and the cutting friction will generate cutting heat, causing the surface temperature of the workpiece to rise unevenly. At this time, the residual stress of the thermal effect causes the surface of the workpiece to participate in the tensile stress, which increases with the increase of the cutting speed. Therefore, by calculating the appropriate cutting processing time and then controlling the cutting speed, the size of the residual stress deformation can be controlled, thereby improving the quality and efficiency of arc workpiece processing.

[0063] Bb: Control the axial feed speed to reduce the efficiency of arc workpiece processing;

[0064] v w ∈(c, d), preferably, in this embodiment 4≤v w≤15mm / s; If the cutting feed speed increases, the amount of metal removed per unit time will increase, the cutting energy will increase, and the cutting temperature will be high, resulting in an increase in thermoplastic deformation. If the cutting feed speed is too low, the processing time will be too long and the production efficiency will be affected.

[0065] Preferably, the arc-shaped workpiece has a thickness of 0.5 to 3 mm and a surface roughness Ra≤1.6.

[0066] The method of cleaning the arc-shaped workpiece and the docking parts is one of chemical cleaning, mechanical cleaning, etc. In this embodiment, a solvent of HF5%+HNO335% is used to chemically remove oxides, oil stains, etc.

[0067] Preferably, the beam current during the positioning welding is 8-10 mA, the welding time is 5s-6s, and the maintenance time is 2-4s; the gap of the weld is 0-0.15 mm.

[0068] The quality inspection operation method includes the following contents:

[0069] Ca: Use a helium leak detector to draw a vacuum to less than 2.0×10-11mbar.L / S, and use alcohol to seal the contact surface;

[0070] Cb: Use helium to purge the weld to detect leaks.

[0071] When this embodiment is in use, the ring-shaped tooling is subjected to solid solution aging to improve the plasticity and toughness of the workpiece, preliminarily remove residual stress, stabilize the tooling structure and size, and obtain a significant solid solution strengthening effect while significantly reducing the energy consumption of heat treatment, thereby obtaining a ring-shaped tooling with excellent mechanical properties. The ring-shaped tooling is then subjected to preliminary rough machining and fine machining in succession to obtain a ring-shaped part, and after rough machining and before fine machining, the ring-shaped tooling is subjected to stable heat treatment to effectively improve the comprehensive mechanical properties and further reduce the residual stress deformation of the parts.

[0072] After obtaining the annular part, the cutting speed is controlled by controlling the cutting processing time, thereby controlling the size of the residual stress deformation, and at the same time coordinating the cutting feed speed, thereby improving the processing efficiency while ensuring the cutting quality of the arc workpiece. The treated arc workpiece and the surface of the docking part are cleaned by a chemical cleaning method. After air drying, the arc workpiece and the docking part are closely contacted and fixed on the fixture, and a flexibly removable isolation pad is added on one side of the weld to effectively prevent damage to the welded part during welding. During welding, a symmetrical welding method is first used to simultaneously position the welding at both ends of the docking, and then fixed welding is performed in the middle of the docking to obtain the processed part, and finally the processed part is subjected to quality inspection. The processing method of the arc workpiece of the present invention first improves the comprehensive mechanical properties of the workpiece, thereby reducing the residual stress deformation of the workpiece during cutting. The welding processing method of the present invention is used to restrain each other by the weld stress, thereby reducing the distortion and deformation, so that the arc deformation is less than 0.5mm.

[0073] Embodiment 2:

[0074] A welding method for thin-walled arc parts, such as Figure 1 As shown, this embodiment makes the following supplements on the basis of embodiment 1: the processing parameters of the rough turning process are: the spindle speed of the outer circle rough turning process is 1100-1200r / min, and the feed speed is F100-F150; the spindle speed of the inner diameter through hole rough turning process is 500-600r / min, and the feed speed is F100-F150;

[0075] Preferably, when rough turning the outer circle / inner diameter through hole, a fine turning allowance of 0.5 to 1 mm is reserved.

[0076] The processing parameters of the finishing turning process are: the spindle speed of the outer circle finishing turning process is 1100-1200r / min, and the feed speed is F30-F45; the spindle speed of the inner diameter through hole finishing turning process is 1100-1200r / min, and the feed speed is F30-F45.

[0077] When this embodiment is used, the processing parameters for the initial rough machining and the secondary fine machining of the ring-shaped tooling are refined so as to obtain a better surface roughness.

[0078] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A welding method for thin-walled arc-shaped parts, characterized in that: The steps include: S1: Prepare profiles: Process matching ring parts tooling according to the outer diameter of the required product; S2: Solution aging of the ring tooling; S3: Perform preliminary rough machining on the ring-shaped tooling: Rough machining is performed on the outer / inner diameter of the ring-shaped tooling according to the outer / inner diameter through-hole parameters of the required product; S4: stabilization heat treatment; S5: Perform secondary finishing on the ring-shaped tooling: Perform finishing turning on the outer / inner diameter of the ring-shaped tooling according to the outer / inner diameter through-hole parameters of the required product; S6: Wire cutting the annular tooling to obtain an arc-shaped workpiece: cutting the annular tooling into two or more annular parts that match the width of the product design size, and then cutting the annular parts into the required arc-shaped workpiece; S7: clean the surfaces of the arc workpiece and the butt joint, position and fix the arc workpiece and the butt joint in close contact on a fixture, and add an isolation pad on one side of the butt joint between the arc workpiece and the butt joint, i.e., the weld; S8: Welding construction: Use symmetrical welding to perform simultaneous positioning welding at both ends of the butt joint, and then perform fixed welding in the middle of the butt joint to obtain a processed part; S9: Quality inspection: Check whether the weld of the processed part is full and leaky, and check whether the weld is leaking; The solution aging treatment method comprises the following contents: Aa: Place the ring-shaped tooling into a heating furnace, heat to 400-500°C, keep warm for 1-4 hours, and cool down after removing from the furnace; Ab: Put the cooled annular tooling into the heating furnace again, heat to 100-135°C, keep warm for 5-20 hours, and cool down after taking out of the furnace; The cooling method includes air cooling, water cooling and furnace cooling; The operation content of the stabilization heat treatment is: placing the ring-shaped component in a heating furnace, introducing stabilizing elements Ti and Nb, heating to 880-1100° C., and keeping the temperature for 2-4 hours; The wire cutting ring tooling includes the following processing requirements: Ba: Calculate cutting time and reduce residual stress and deformation; Bb: Control the axial feed speed to reduce the efficiency of arc workpiece processing; The calculation formula of the cutting processing time is: y2=L / v w ; y2 is the processing time, in seconds; L is the part width, in mm; v w is the axial feed speed in mm / s.

2. A welding method for thin-walled arc-shaped parts according to claim 1, characterized in that: The method of cleaning the arc-shaped workpiece and the butt joint is one of chemical cleaning and mechanical cleaning.

3. A welding method for thin-walled arc-shaped parts according to claim 1, characterized in that: The beam current of the positioning welding is 8-10 mA, the welding time is 5s-6s, and the maintenance time is 2-4s; The gap of the weld is 0 to 0.15 mm.

4. A welding method for thin-walled arc-shaped parts according to claim 1, characterized in that: The quality inspection operation method includes the following contents: Ca: Use a helium leak detector to draw a vacuum to less than 2.0×10-11mbar.L / S, and use alcohol to seal the contact surface; Cb: Use helium to purge the weld to detect leaks.

5. The welding method for thin-walled arc-shaped parts according to claim 1, characterized in that: The processing equipment for the preliminary rough machining and the secondary finishing is a CNC lathe; The wire cutting processing equipment is a CNC wire cutting machine tool.

Images